# Sebastián Fernández de Medrano

Sebastián Fernández de Medrano (24 October 1646 – 18 February 1705) was the president and sole-director of the first modern Royal Military and Mathematics Academy of Brussels in Europe during the reign of Charles II of Spain and briefly Philip V of Spain. Sebastián was a military leader, Royal Master of Mathematics in the states of Flanders, General Prefect of the king, geographer, cartographer, Captain and Maestre de campo of the Spanish Tercio, inventor, General of Artillery, Chief Artillery Engineer of the Kingdom, author, and military architect in the Empire of Spain.

## Poetic tributes to Medrano

There are various poems and sonnets dedicated to Medrano. An allegory From Chrysostomus de Monpleinchamp, the kings herald in 1700:
   "To the most blind, in the army of the king, as the general prefect. Mercury, Nereus, and Mars vied for his honor, but Themis settled their disputes, declaring that whatever wealth radiated to them, MEDRANO revealed. The gods were not disappointed, and Mercury put down his arms, Mars laid aside his weapons, and Nereus presented a shield. MEDRANO laid at their feet heaps of spoils, and Themis built a triple trophy, crowning him with a triple diadem. The first crown bore the insignia of the defeated Mars, the second that of Mercury, and the third that of Neptune. Fame heard and flew, marveling at the unusual trophy, and filled the world with a thousand trumpets. God overpowered their voices, carrying the light throughout the heart and from there surpassed even the sharpest-eyed lynxes."
A dedication in the form of a sonnet from Sebastián's disciple in 1688:
A sonnet from Manuel Pellicer y Velasco, a disciple and friend of Sebastián Fernández de Medrano, written in 1688:
   " A torch that, when extinguished, you shine brightly, a Sun that, amidst clouds, turn [to] your rays, Cupid of the sciences that you adorn, Eloquence and all its greatness. Just fame of immortality you deserve, And applause and fame together conspire, Reducing to the harmony of the lyre, The harmonious sphere that you present here. With eight volumes, With Spanish affection, you have enlightened the martial school, And your industrious and versatile genius soars, To that of Apollo with which you have achieved, after sailing so long without a sail, to remain crowned with sacred Daphne."
From Chrysostomus de Monpleinchamp, the kings herald in 1701:
   "To Master Sebastián Fernández de Medrano, both blind and keen-sighted, in the King's Army, as the General Prefect: Veiled by clouds, the sun preserves the mortal lights, and both worlds twinkle in alternation. Similarly, Medrano, deprived of his twin eyes, wanders the House of the Sun and Uranus with his ingenious mind."

## Geographer

The Colonel of Engineers Joaquín de la Llave held a conference to establish Sebastián Fernández de Medrano as a geographer on 28 November 1905. Colonel Joaquín de la Llave provided a comprehensive overview of the life and achievements of Sebastián Fernández de Medrano, declaring his significant contributions as a geographer and military engineer. Held to honor Sebastián's interdisciplinary impact on military architecture and geography, the conference focuses on his scholarly works and educational legacy.
Joaquín de la Llave discussed Medrano's enduring influence on the methodologies employed in military academies and his pivotal role in training engineers and military personnel. Regarding Sebastián Fernández de Medrano, Colonel de la Llave made a statement in his 1905 conference:
   "His books are clear and methodical. The doctrine is presented with great precision and clarity, and therefore, as textbooks for the Academy of Brussels, they represent a considerable advancement. It is also important to note that at that time, geographic studies were very neglected. In most European countries, geography was not studied, or if it was, it was done in such an elementary way that it was far from what Medrano taught his disciples, which, while not perfect knowledge, represented a significant advancement over what had been done until then. Therefore, I believe that, without taking away the place that corresponds to him, Fernández de Medrano cannot be denied the status of a geographer, and a geographer of certain importance among ours; he represents a marked progress in Spanish geography, in its didactic part, and deserves some tribute, some consideration from the Geographical Society, which is the purpose that guided me in giving this lecture."
Colonel de la Llave acknowledges Medrano's Academy and credits him with significantly enhancing military training by combining practical and theoretical education. Medrano was credited with authoring influential textbooks that combined detailed geographical descriptions with practical military applications. His works included "La Geografía ó moderna descripción del Mundo y sus partes," and "Breve descripción del mundo, ó guia geographica de Medrano" dedicated to King Charles II of Spain, which, according to Colonel de la Llave, were instrumental in advancing geographic science during his era.
A poem from the "Geography of Medrano" dedicated to Charles II of Spain by Sebastián Fernández de Medrano in 1688:
       "My lord, deity of Austria, to you with sincerity, My humble chest renders adorations, And with loyal affection for offerings, Consecrates upon your altars this globe. If only, my lord, I could make it so, That yours were the variety of its regions, And expand the domain of your lions, In another that surpasses the first. I dedicate to you in [this] abbreviated volume, Trusting only in your clemency; For if I lose myself in such a vast world, Excused by blindness and by zeal, In you, Charles without Second, I will be found."

## Patronage

The Medrano family were the patrons of Sebastián. According to a later inquiry documented from the middle of 1719, at the age of 15, Sebastián supposedly traveled to Madrid accompanied by a distinguished and noble gentleman from the House of Medrano. The Medrano family, well known for producing military leaders, and for their administration in government, academic contributions and virtues, became patrons of Sebastián Fernández, securing a position for him at the age of 21 as an ensign in the company of Juan de Meneses under the tercio commanded by the Master Field Marshal Lord Francisco Antonio de Agurto Salcedo Medrano, the future governor and captain general of the Habsburg Netherlands.
The Most Illustrious Lord Antonio Vélaz de Medrano, I Marquess of Tabuérniga became the governor of Nieuwpoort in Flanders. Under the protection of the House of Medrano, Sebastián then traveled to the States of Flanders, where Sebastián became known as Sebastián Fernández de Medrano. He continued to use this name, which was initially bestowed upon him by the original Medrano gentleman to help establish an identity for himself.

## Autobiography

Sebastian Fernandez de Medrano left his own autobiography. His autobiography was later published in "Noticia biográfica de Don Sebastián Fernández de Medrano" by Antonio Rodríguez Villa, published in Madrid in 1882 by M.G. Hernandez. It is part of the Americana collection and is held in the collections of Harvard University.

### Background

Sebastian Fernández de Medrano was born in Mora, within the ecclesiastical jurisdiction of Toledo. He was the son of Sebastian Fernandez de Mora and Isabel de Medina, both natives and residents of the town of Mora, province of Toledo. His birth is recorded on October 24, 1646, as detailed in the sixth baptismal book of the local parish. Driven by what he describes as "zeal and glorious ambition," Sebastian Fernández de Medrano found deep satisfaction in exploring the extensive literature on the art of warfare.
His self-study was spurred by the recognition of the "great usefulness it was to the warrior to understand the parts of mathematics that pertain to the martial art." He was particularly drawn to the strategic elements of military architecture, including the construction and tactics involved in fortifying and besieging strongholds.
Colonol de la Llave put forth the notion that Sebastián wanted to understand what he was doing and seeing when he found himself in war, and therefore turned to the books he could gather. The Colonol suggested that he might have completed this study during the five or six years he remained in Madrid attending a military academy that existed during those years, founded at the end of the 16th century, under the direction of captain Cristóbal de Rojas.

### Military career

From a young age, Sebastián Fernández de Medrano was drawn to royal service, beginning his military career at the age of fifteen. He participated in four military campaigns across Castilla la Vieja during 1660 and 1661, serving under the governance of the Duke of Osuna, primarily in roles stationed at simple garrisons along the frontier.
Referring to Castilla la Vieja, Colonel de la Llave suggests that Medrano participated in military campaigns across the provinces of Zamora or Salamanca.
This early exposure to military life marked the beginning of a distinguished and eventful journey in service to the Spanish crown. His commitment to military sciences led him to Madrid, where, inspired by "the whims that had taken root in my head," he prepared for an auspicious military opportunity. Sebastián recalls how this opportunity materialized in 1667, when the court was raising a new tercio of infantry destined for service in Flanders under His Majesty. Sebastián Fernández de Medrano recounts relying on Fernando Miguel de Tejada, who "had known me when I was the General Field Master in that frontier," to secure his position. He successfully became an ensign and obtained a flag in the company of Juan de Meneses.
In 1668, his ambitions took him to Flanders, where he joined the company of Juan de Meneses in the tercio commanded by the Master Field Marshal Lord Francisco Antonio de Agurto Salcedo Medrano, later known as the Marquess of Gastañaga and Governor and Captain General of the Habsburg Netherlands (also known as the Low Countries). Sebastian Fernández de Medrano reflected deeply on his experiences and the influences that shaped his military career, noting the profound respect he held for the Marquess of Gastañaga, the Governor and Captain General of Flanders. Sebastián wrote:
   "Since the aforementioned Lord Marquess loved the glory of the Military so much...he highly esteemed the officers of his tercio who were inclined to service and applied to everything required to acquire their good judgment."
This admiration led to a reciprocal relationship, as Medrano was "fortunate enough to earn his favor," which significantly impacted his military trajectory. Throughout his service, Sebastián was consistently involved in critical decisions, he wrote:
   "The Marquess of Gastañaga always took me with him on campaigns and visits to garrisons, not making a decision without favoring my opinion."
This mentorship and collaboration continued until the death of the Marquess. Despite this supportive environment, Medrano faced skepticism from his peers regarding his intense focus on mathematics, a subject he pursued with relentless dedication despite being deemed "crazy" by other officers.
His persistence paid off, allowing him to achieve "a decent theoretical understanding of fortification and artillery use, as well as some practical experience in the construction of fortifications." Medrano's efforts were particularly notable in a context where many foreign engineers lacked depth in their knowledge, a fact he discerned through his evaluations of works commissioned by the Count of Monterrey.
He recalls his experiences during these years, from witnessing the brief war following the breach of the Peace of the Pyrenees to the subsequent Peace of Aix-la-Chapelle, he believes this enriched his understanding and application of military engineering in a transformative era of European warfare. Sebastián Fernández de Medrano trained soldiers and officers from all over Europe, especially the Army of Flanders.

### Establishment of the Royal Military and Mathematics Academy of Brussels (1675)

Sebastian Fernández de Medrano's military prowess and reputation reached notable figures such as Diego Gomez de Espinosa, Luis de Acosta Quiroga, and Joseph Manrique, influential field marshals who recognized his capabilities. During a period when these marshals were organizing regiments of "cadets," consisting of nobles or officers' sons being trained in martial arts and seamanship, Medrano's expertise became particularly valuable. His renown led them to propose to the Duke of Villahermosa the establishment of a military academy to modernize military training:
   "...the field marshals informed the Duke of my ability and suggested that instead of granting me leave [to Spain], he should establish a military academy for the army, where we could acquire a skill that was so lacking in the new way of waging war. The Duke agreed with this suggestion and immediately summoned me. He said that it was good timing for me to come to Spain, as he intended to establish a martial seminar for the army, and that he wanted me to be the director."
Sebastián Fernández de Medrano's return to Spain coincided with the Duke's plans to establish a "martial seminar for the army." Despite Sebastián's initial reluctance to lead such a significant endeavor, citing his doubts about handling the "difficult task," the Duke persisted. Encouraged by this confidence in his abilities, Medrano accepted the challenging role of director for the new academy, stepping into a pivotal position that would influence the future of military training in Spain. The first modern Royal Military and Mathematics Academy of Brussels was established in Brussels, Habsburg Netherlands by the sole-director Sebastian Fernández de Medrano at the request of Carlos de Aragón de Gurrea, 9th Duke of Villahermosa, in order to correct the shortage of artillerymen and engineers from the Spanish Tercio. Medrano wrote in his autobiography:
   He [the Duke of Villahermosa] said that it was good timing for me to come to Spain, as he intended to establish a martial seminar for the army, and that he wanted me to be the director. I excused myself, saying that I did not feel capable of undertaking such a difficult task, but he insisted, saying that he knew what I was capable of, and that when he was the general of the cavalry during the siege of Audenarde, he had seen me hit fourteen point-blank shots from a cannon (which I had done by order of the Duke of Montalto, who was the field marshal in charge of the trenches). With these circumstances, I could not refuse and accepted the offer.

### Director of the first modern military and mathematics academy in Europe

Following the establishment of his military academy in 1675, the director Sebastian Fernández de Medrano recalls how he quickly solidified his influence and reputation within the military educational realm. His efforts were met with substantial success, drawing a "large number of officers from all ranks" to the academy. This initiative was further bolstered by the publication of his book, "Rudiments of Geometric and Military Principles." The book resonated widely, praised for its clarity and accessibility, and became a cornerstone of the curriculum. Medrano noted its success, writing that "within a year many had benefited from the new method that I had established, which was designed to be so straightforward that even the least intelligent learned from it very quickly."
By 1688, the Army of Flanders, educated by Medrano and led by the Marquess of Gastañaga, numbered 25,539 officers and men and by 1689 the total strength of his army increased to 31,743 men. This was the peak strength of the Army of Flanders in the Nine Years' War.

### Inspiration

Don Sebastián Fernández de Medrano was inspired by Juan Domingo de Zuñiga y Fonseca, Count of Monterey, president in the Supreme Council of Flanders. Sebastián Fernández de Medrano writes to Juan Domingo de Zuñiga y Fonseca:
   "...seeing the generosity with which Your Excellency favored the diligent; it ignited in me such ambition for glory, to unite the practice of my services with the theoretical knowledge of the Mathematical Disciplines belonging to the Artillery. Supported by this, His Majesty granted me the establishment of the New and Royal Academy, of which I am the Director. Through my presence and writings, which I have published on these matters, many individuals capable in Military Architecture have emerged, not only for His Majesty's borders but also for those of the Allied Princes, who have made use of them. It is well known that in the past we had to seek them from abroad."

### Benefactor of the armies in Europe

Director Sebastián Fernández de Medrano's influence on the generals and armies of Europe was significant, he writes:
   ... upon being informed by my generals, I owed to their magnanimity the noble attribute of being named in their Royal Dispatches as a benefactor to their armies.

### Captain of Tercio

The academy's fame and the widespread adoption of his educational methods earned Medrano significant recognition, culminating in Carlos de Aragón de Gurrea, 9th Duke of Villahermosa, Governor and Captain General of the Netherlands, Burgundy, and Charolai, bestowing upon him the command of a tercio infantry company. The culmination of these achievements was marked by the granting of a patent on April 30, 1679:
   "...Considering these and other good qualities required and desirable for this position in you, Don Sebastian Fernandez de Medrano, taking into account how well you have served His Majesty (...) I have chosen and appointed you as the Captain of the said company, in the place of the said Don Juan de Garcerán, giving you and granting you (...) the said Tercio." - The Duke of Villahermosa, Count of Luna

### Duke of Villahermosa and Charles II of Spain

To solidify the achievements and secure the future of the military academy he had initiated, His Excellency, Carlos de Aragón de Gurrea, 9th Duke of Villahermosa, decided to report to King Charles II the successful outcomes observed since the academy's inception. Recognizing the importance of Sebastian Fernández de Medrano's continued leadership and contribution to this innovative educational endeavor, the Duke recommended that Medrano be allowed to resume his duties at the academy, focusing on the necessity for his service in this role for the betterment of the king's military. In response, King Charles II issued a royal command affirming the Duke's proposal. The King's order, dated November 16, 1679, from Burgos, explicitly supported the continuation of Medrano's work, stating:
   "With regard to what you report in your letter about the convenience that will result from Captain Sebastian Fernandez de Medrano continuing to teach Mathematics in those states, and to this end assigning him the salary of a live captain and providing him with his company, I have agreed to what you propose."
The King further instructed the Duke to implement the necessary arrangements to ensure Medrano received his captain's salary and commanded his company, overriding any previous orders that might conflict with this decision. Moreover, King Charles II emphasized the broader strategic importance of fostering such educational initiatives, urging the Duke to "favor greatly those who dedicate themselves to this profession, as it is necessary to have qualified individuals in this field everywhere." The King's vision of enhancing the military's capabilities through specialized education and training was recognized as a critical role of skilled professionals like Medrano in advancing the military's effectiveness and readiness.

### Achievements

Recognizing the significant progress achieved by the Royal Academy of Mathematics, the Duke of Villahermosa once again conveyed his commendation of Sebastian Fernández de Medrano's efforts to King Charles II in a persuasive letter. In his correspondence, the Duke of Villahermosa praised Medrano's dedication and effectiveness, particularly the academy's impact on enhancing military expertise within Spain. The Duke wrote in Brussels, on 18 July 1680:
   Sir, when I established the Royal Academy of Mathematics in these States by your order and approval, I also informed you of the choice I had made of Captain Sebastian Fernandez de Medrano to teach this subject to the officers and soldiers of the army. In the limited time that the military have attended, many have become very proficient in the understanding of the arts that make a soldier capable in his profession... the proof of having already sent some engineers to other armies, who with the experience previously acquired and the theory of mathematics, have advanced in such a way that it has been achieved that today Your Majesty no longer needs to rely on engineers and artisans from other nations, which carries so much risk of confidence, having expert Spaniards in these matters.
This training included crucial skills like military architecture, the method of squaring, and the handling of artillery. The Duke also celebrated the strategic autonomy gained through the academy's success. In Brussels, the Duke of Villahermosa urged the King to recognize and reward Medrano's contributions, writing on July 18, 1680:
   I must implore Your Majesty to deign to bear this merit in mind in order to qualify it with remuneration, as it is such an effective means for the advancement of the arts that lead to Your Majesty's Royal service to signalize them in the reward and prize of their sovereign justification and greatness.

### Contributions to the field of military sciences

Honored by the recognition and support he received, Sebastian Fernández de Medrano was inspired to further develop his expertise and contribute to the field of military sciences. He embarked on publishing various works on fortification, geometry, battalion formation, and the use and practice of artillery and mortars. Medrano also extended his scholarly pursuits to include geography and navigation, albeit at the significant financial cost of his wife's inheritance. These efforts led to the training of a substantial number of engineers whose skills were in high demand. Medrano proudly noted:
   "As a result, a great number of engineers were trained, and His Majesty and later the Holy Roman Emperor and Princes of the League requested their services for all the borders of their dominions." The quality and effectiveness of these engineers were such that previously, "we had to beg for engineers because there were no subjects who understood this field."
One of Medrano's trained engineers, named Reysemberg, achieved notable distinction by becoming the General Engineer for the Emperor, and another served King James of England. Their expertise was further validated during the sieges of Mainz and Bonn, where they received commendations for their work. Medrano recalled, "For the sieges of Mainz and Bonn, the Duke of Lorraine requested their services, and they worked so well that they earned the applause of that great champion and the Duke of Bavaria, as stated in a letter from the Elector of Trier on October 2, 1689."

### Medrano accompanies the Marquess of Gastanaga

Medrano's personal involvement in military operations continued as he accompanied General Field Marshal Francisco Antonio de Agurto Salcedo Medrano on visits to Cologne, Bonn, Trier, and Koblenz, he recalls his active role in applying and promoting military engineering across Europe.
During a visit to Koblenz, Sebastian Fernández de Medrano encountered an unexpected recognition of his expertise. Johann Hugo von Orsbeck, Archbishop-Elector of Trier, upon learning of Medrano's presence through officers who had previously been his students, sought his expert opinion on the fortifications of Koblenz and its prominent castle, Ehrenbreitstein.
Initially, Medrano expressed reservations, modestly stating, "I replied that I did not have enough knowledge in the military to give an opinion on fortification," however, the Elector persisted by recalling Medrano's credentials as the Director of the Royal Academy of Brussels and expressing trust in his judgment due to his reputation. Medrano wrote:
   He [von Orsbeck] insisted, saying that I was the Director of the Royal Academy of Brussels and that, being an Austrian prince, he could trust my judgment.
Encouraged by this confidence, Medrano then offered his recommendations for necessary repairs and improvements to the fortifications. The discussions concluded with an agreement that Medrano would recommend the most capable individuals for the fortification work when the Elector requested.

### Medrano's disciple Juan de Ortega

Later on, when Medrano sent him one of his students, Juan de Ortega, to assist with the attack on Mainz, he was killed in action. The Duke of Lorraine expressed his regret, saying "that a valuable man had been lost." Medrano had correspondence with the Elector, who had sent two of his subjects to Medrano's academy to be trained, and in one of the Electors letters, he mentioned Don Juan de Ortega: "He could have given with time the signs of great services to the King, his master, where the glory would always redound to his first Director [Sebastián Fernández de Medrano]."
In the letter dated August 2, 1689, Juan Hugo of Orsbeck, the Archbishop Elector of Trier, expressed his deep appreciation and respect for the training provided by the Director of the Royal Academy of Brussels, Sebastian Fernández de Medrano. He acknowledged the significant contributions of Juan de Ortega, a disciple of Medrano, whose military expertise greatly benefited the Archbishop's fortifications, thanks to Medrano's exceptional mentorship. The Archbishop lamented Ortega's untimely death, noting his potential for future excellence and the loss felt by high-ranking military figures like the Duke of Lorraine.

### Savoyard commendation

Sebastian Fernández de Medrano recalls a notable instance where a disciple of his, appointed to the siege of Casal di Monferrato, earned the commendation of the Duke of Savoy. This success, Medrano explains, was a direct result of his extensive firsthand experience with generals during various campaigns, notably up to the Peace of Nimeguen. During these campaigns, Medrano wrote:
   I had the opportunity to observe, acquire, and personally demonstrate everything pertaining to the art and science of engineering."

### Loss of eyesight

Despite achieving much in his field, Medrano's relentless dedication took a toll on his health, leading to the loss of his sight:
   Although I was later unable to continue participating in campaigns due to losing my sight from tireless study and work, heaven increased my spiritual vision to continue with the same and even greater fruit of serving the king by directing the Royal Academy, from which so many engineers have emerged and various works of curiosity, ease, and usefulness have been published for my disciples and for the public.
However, he poetically notes that this physical limitation only enhanced his "spiritual vision," enabling him to continue his work with even greater determination. He shifted his focus towards directing the Royal Academy, where he successfully mentored numerous engineers and oversaw the publication of various significant works that contributed to the field.

### Salary payments

Medrano's efforts and their impacts did not go unnoticed; they were well-documented and reported to the king by his generals. Recognizing the challenges posed by his blindness and his inability to personally manage financial support for his initiatives, the king extended his royal clemency. On May 20, 1688, he issued an order acknowledging Medrano's invaluable service and provided him with the necessary support to continue his work at the Academy, thus ensuring that his contributions would endure despite his personal hardships.
On May 20, 1688, King Charles II addressed an issue of delayed salary payments to Sebastian Fernández de Medrano, the Captain and Director of Mathematics. He directed the Marquess of Gastañaga, with strong terms of urgency, to ensure that Medrano received his monthly stipend of 500 escudos regularly.
The King emphasized that this payment should be "a fixed and ordinary burden so that he may receive it without any further requirement than his payment order," acknowledging his recognition of Medrano's significant contributions, merits and the unique benefits his Academy provided, which His Majesty described as unparalleled and immensely beneficial ("which cannot be exemplified by any other").

### Appointment as Maestro de Campo (1689)

The following year, on May 18, 1689, in acknowledgment of Medrano's two decades of service in various military roles and his exceptional leadership at the military academy, King Charles II awarded him the highest rank of the Maestre de Campo of Spanish Tercio:
   Don Carlos, by the grace of God, King of Castile, of Leon, of Aragon... etc. In consideration of what you, Don Sebastian Fernandez de Medrano, have served me for twenty years in my army of Flanders, with the ranks of soldier, live and reformed ensign, officer of the Artillery, and captain of Spanish infantry, and for currently serving as Director of the military Academy established in that army, with particular dedication, diligence, and universal benefit of the profession: I have decided to grant you the rank of Maestre de Campo of Spanish Infantry, so that you may continue in your service with greater distinction, without this serving as an example for any other person: Therefore, I charge and command ... that you be recognized, respected, and acknowledged as such Maestre de Campo of Spanish Infantry ... and that the hundred escudos per month for your maintenance that you currently receive and are assigned in the almodiacion ... continue to be granted to you, so that you do not fail to attend to an employment so necessary and so much in my service ... Given in Buen Retiro on May 18, 1689. - I, the King
King Charles II of Spain's decree assured the continuation of his maintenance allowance of one hundred escudos per month. This promotion was meant to enable Sebastián Fernández de Medrano to serve with greater distinction.

### Letter from the Marquess of Gastañaga

In a letter dated 31 October 1691, the Marquess of Gastañaga, Don Francisco Antonio de Agurto Salcedo Medrano, advocated on behalf of Sebastian Fernández de Medrano to King Charles II of Spain:
   "The benefit that Your Majesty's service is experiencing is evident, for when there was a shortage of Spanish engineers in Your Majesty's armies, Don Sebastian has produced so many and such distinguished disciples, officers and soldiers of this army, not only in the art of fortifying, squadroning, using artillery, fire tricks, how to throw bombs and carcasses (a type of incendiary bomb), but also in what concerns navigation, that Your Majesty can avail yourself of all those that you need. He has published at his own expense eight books, all related to these military arts, with great clarity for the shortest teaching and understanding of the disciples, which has given him so much credit among foreigners that many princes desire his disciples and send subjects to his Academy to learn from him..."
The Marquess of Gastañaga praised Medrano's increasing merit and the continual excellence he displayed in his military and academic endeavors, praising his "zeal" and "valor" both in action and in his dedication to the mathematical arts. The Marquess of Gastañaga particularly noted Medrano's contributions to the military through his role as Master Director of the Academy, where he significantly enhanced the Spanish military's capabilities.
He credited Medrano with remedying the shortage of skilled Spanish engineers by training many distinguished officers and soldiers in comprehensive military skills, ranging from fortification and artillery to navigation. Medrano's commitment extended to publishing eight books on these subjects at his own expense, which were lauded for their clarity and practical utility, gaining him an international reputation. Despite his blindness—a condition brought on by his relentless work and study—Medrano's dedication remained unwavering, continuing to serve with the same "fruit, ardor, and zeal" as before. The Marquess of Gastañaga argued that any support given to Medrano, who also had a large family to support, would be a fitting testament to the "royal benevolence and greatness" of the King. The Marquess of Gastañaga assured that such favors would be appropriate and justified.

#### Royal favors from the King

Sebastian Fernández de Medrano's continued dedication and service were met with further royal favor when King Charles II agreed to increase his monthly salary by forty escudos. Recognizing not only Medrano's contributions but also the personal sacrifices made by his family, the King extended his compassion towards Medrano's wife and four daughters.
The Marquess of Gastañaga had noted the substantial financial contributions from Medrano's wife's inheritance—more than eight thousand escudos—used for publishing educational materials, which necessitated a significant investment due to the complexity of the subjects and the need for translation into Spanish. In response to these circumstances and the potential future needs of Medrano's family, the King granted them a share of half of Medrano's adjusted salary of one hundred and forty escudos per month. This provision was designed to ensure their financial security, stipulating that the amount be divided equally among his wife, Doña Mariana, and daughters, Doña Catalina, Doña Bernarda, Doña Irene, and Doña Eufemia Fernández de Medrano.
This arrangement also included a succession clause, allowing them to inherit from each other until only one remained. This royal decree, issued on July 14, 1692, in Madrid, not only provided for Medrano's immediate family but also acknowledged his long-standing service and the unique value of his contributions to the military through his expertise in mathematics.

### Testimony of the Elector of Bavaria

As the Most Serene Elector of Bavaria had seen Medrano's disciples work in Hungary and Germany, he informed His Majesty shortly after he had taken over the Government of Flanders, in the following letter:
   "Sir, the Field Marshal Don Sebastian de Medrano, Director of the Royal Academy of Mathematics in these Kingdoms, is a person of such qualities and services that Your Majesty is not only aware of them through the reports and information that the Generals and Officers of this army have provided, but also through the very effects that his ingenuity and application have benefited the Royal service of Your Majesty. So, even though I can omit the detail of repeating to Your Majesty what convinces me of the quality of Don Sebastian's merits, I do not hesitate to bring them to Your Majesty's gracious attention so that you may keep them in mind on the occasions that arise to reward them, being certain that not only will it be a worthy exercise of Your Majesty's Royal justification, but also the most useful application, as it will serve to invite encouragement and imitation. God save Your Majesty as I need. Brussels, January 26, 1694." - Maximilian II Emanuel, Elector of Bavaria

### Appointment as Battle General (1694)

This representation by the Elector of Bavaria was so effective that, accompanied by others at that time from the Lord Prince of Vaudemont and Marquess of Bedmar, and continuing to justify His Majesty, he honored Medrano again in 1694 (By Royal decree of March 17th) with the rank of Battle General. Having gone to thank His Serene Highness for the favour he had shown him, Medrano found that he had been promoted without the corresponding salary for the rank, and the Elector of Bavaria was surprised by this circumstance, having believed that the promotion came with a salary, based on his good offices with His Majesty in favour of his services. The Elector of Bavaria immediately ordered Sebastián to draft a Memorandum for the King and take it to him. When he executed it, it was handed over to His Majesty on May 20 of the same year with the following representation from Maximilian II Emanuel, Elector of Bavaria:
   "Sir, the Sergeant General of Battle Don Sebastian Fernandez de Medrano, Director of this Royal Military Academy, has asked me to pass on to Your Royal hands the attached Memorandum, in which he requests that Your Majesty be pleased to grant him the salary of Sergeant General of Battle for the reasons he presents; and since I find them very worthy of Your Majesty's Royal clemency, both because of the large family and expenses he has while continuing to direct the Academy, I must hope that Your Majesty will continue to honour him by granting him the favour he requests. God save... etc."
As a result, His Majesty granted Sebastián Fernández de Medrano a monthly salary of three hundred escudos, which belong to the rank of General de Batalla, and to continue in His Royal decree the charity granted to his wife and daughters, ordering that the said three hundred escudos be paid to him and his family through the same means and in the same manner as the previous one hundred and forty escudos. Medrano wrote:
   ... this singular circumstance could not serve as an example for others, as I alone was judged to be of general benefit to His armies, a circumstance that I have in all my decrees, and with which the payment to me and my family has always continued.

### Letter from the Prince of Vaudemont (1696)

Motivated by the recent display of His Majesty's benevolence and support, Medrano remained steadfastly dedicated to the Academy. He continually aimed to simplify the learning process for his students, ensuring they understood the sciences in the most effective, clear, and concise manner. Recognizing both Medrano's dedication and the tangible benefits that subsequently arose in service to His Majesty, the Elector of Bavaria, Marquess of Bedmar, and Prince of Vaudemont also deemed it appropriate to bring this to His Royal Highness's attention, as evidenced by the subsequent letter from Prince de Vaudemont:
   "...although on different occasions Your Majesty has shown appreciation for the intelligence, rightly justified by the reports and information that have been presented to Your Majesty about the person and qualities of Sergeant General of Battle Don Sebastian Fernandez de Medrano, director of the Royal Academy of Mathematics in this Court, and although the transcendent benefit that his intellect and abilities bring to Your Majesty's royal service needs no further qualification than that which he already has in this army and in all the courts of Europe, I have nevertheless thought to add to the many and authoritative declarations that endorse his proficiency in all the subaltern faculties of mathematical science..." Brussels, January 20, 1696 - Charles Henri of Lorraine, Prince of Commercy, Prince of Vaudémont

### Appointment as General of Artillery

Continuing his efforts until the year 1699, when Lord Carlos II passed away, Medrano started to seek recognition for his greater merit and services, specifically requesting the rank of General of the Artillery. During this time, members of the Council of State showed considerable favor towards his request, both before and after the King's death. This support is evidenced by the following statement from Lord Cardinal on June 18, 1699: "I hope that you will achieve the rank of General of Artillery that you are seeking, and considering this pretension to be very justified, I will attend to you willingly, showing my appreciation for your person." The Duke of Montalto also supported the promotion, stating:
   "...If the reward for your useful and commendable work depended on my discretion, you would have the benefits you deserve, and if I were in the Court, I would be your agent in the request for the rank you are seeking, because, as the King, whom God protects, has foreseen and I know, you set an example for no one else, and I promise that you will achieve what you desire."
In a similar manner, prominent figures including the Count of Aguilar, the Count of Monterrey, the Duke of Medina Sidonia, the Count of Fuensalida, the Marquis of Casteldosrius, D. Antonio de Ubilla, and D. Crispin Gonzalez Botello wrote almost the exact same thing.

### Salary under King Philip V of Spain

Following the ascension of King Philip V, the Elector of Bavaria and the Marquess of Bedmar brought to the new king's attention the same commendations they had presented to the previous monarch. Sebastián Fernández de Medrano includes two lengthy letters of recommendation from the elector of Bavaria and the Marquess of Bedmar, dated March 2 and July 21, 1701, which reiterate the merits and services of the director of the Academy.
Meanwhile, a new government structure was being established, and the salaries of Generals and Ministers were temporarily suspended by an order from His Royal Highness. However, an exception was made for Don Sebastian Fernandez de Medrano, the General of Battle and Director of the Military Academy, who was permitted to continue collecting his salary as usual. This exception was formalized in a decree issued on March 20, 1701, which instructed the Council of Finances to ensure that there was no hindrance in his salary collection, thereby maintaining the status quo.
After learning about the salary adjustments in Flanders, the Marquess of Gastañaga D. Francisco Antonio de Agurto Salcedo Medrano Zuniga informed Medrano on September 22, 1701, that although a universal reduction in ranks and corresponding salaries was to be implemented, Medrano's salary and emoluments would be maintained as an exception. This decision was backed by those who recognized Medrano's merits and were inclined to support him due to his justifications and the goodwill he had accrued.
Armed with this assurance, Medrano communicated the news to the Marquess of Bedmar, seeking to ensure that the latter's patronage and protection would continue. In response, Bedmar instructed Medrano to prepare a memorial, which, after consultation with the Master General of the Field, Prince of Tserclaes, was submitted to King Philip V. This representation, dated January 6, 1702, in Brussels, prompted the king to confirm the special arrangement regarding Medrano's salary, which, according to Medrano:
   "Our Lord Philip V, conformed with said representation, he confirmed the privilege and uniqueness with which I received my salary along with my family."
King Philip V clearly stated in his Royal Decree:
   "I agree with the consultation of the Council of State and the Count of Monterrey regarding the salary of Don Sebastian Fernandez de Medrano, and give the necessary orders to execute it, both to the Marquess of Bedmar and as long as it does not oppose any others granted by King Christianissimo and my grandfather."
Continuing his support, the Marquess of Bedmar proposed to secure the same arrangement from Philip V of Spain, instructing Medrano to collaborate with the Ambassador in France, the Marquis of Casteldosrius. Medrano complied by sending a memorial to His Most Christian Majesty, facilitating further diplomatic efforts to ensure the continuation of his special salary provisions.

#### Endorsement by the Marquess of Casteldosrius

In his communication dated April 7, 1702, the Marquess of Casteldosrius informed Medrano that efforts had been made with His Most Christian Majesty to ensure the continuation of Medrano's salary and privileges. Following this, the Marquess of Bedmar acted to enforce these directives, including a copy of the decree in the memorial Medrano presented, thus securing the arrangements. Regarding this process, the Marquis of Casteldosrius wrote to Lord Sebastián Fernández de Medrano:
   "My Lord, in accordance with what I previously informed Your Lordship... His Most Christian Majesty has instructed his Ambassador in Spain to recommend Your Lordship's person and merits to the King, Our Lord, so that he may be pleased to issue orders for Your Lordship to receive your salary as before and for Your Lordship's wife to retain the granted grace of enjoying half of it after her days."

### Death (1705)

He experienced a stroke in 1704 that severely impaired his speech and memory, to the extent that he could no longer remember the prayers he usually recited with devout Christian faith. This tragic incident, along with his earlier loss of sight, left him in a profoundly sorrowful and lamentable condition until his death on February 18, 1705, in Brussels. He was laid to rest in the church of the Discalced Carmelites in the same city, which is part of the collegiate and parish church of San Miguel de Gudile.

### Wife and children

Sebastián Fernández de Medrano was the father of four daughters, Doña Catalina, Doña Bernarda, Doña Irene, and Doña Eufemia Fernández de Medrano. After the misfortune that befell her husband, Doña Mariana de Saseguen, originally from Alost in the Brussels diocese and daughter of Gaspar de Saseguen and Susana de Riech, moved to Spain to live with her daughter, Doña Catalina de Medrano. Catalina was married to Mr. José de Pedrajas. Doña Mariana stayed with them until her own passing on April 3, 1719, in Madrid. She was interred in the church of the Agonizing Fathers. Throughout the tumultuous period, the wife and daughters of the distinguished general were granted a monthly pension of seventy silver escudos. This pension was disbursed by the main treasury of the Kingdom of Valencia and sourced from confiscated properties.

## 'First system' of fortification (1687)

The architect, military engineer and lieutenant general Juan Martin Cermeño argued that Sébastien Le Prestre, Marquis of Vauban's well-known ‘first system’ of fortification, recognized for its orillons and curved flanks and published in a 1689 Amsterdam pirated edition, had actually been preceded by Sebastian Fernandez de Medrano's work in Brussels in his academic book "El Ingeniero Practico," published in Brussels in 1687. Medrano, who was the director of the Royal Military Academy of the Spanish Netherlands, had developed similar fortification concepts.
Cermeño noted that while Vauban might have refined ideas originally suggested by Marchi, Medrano's designs were also highly advantageous, albeit somewhat complex to implement. However, Medrano's contributions were overshadowed, according to Cermeño, by the misfortune of being Spanish and working during a period when Spain's military innovations were not as celebrated as in other eras, as noted in "La Mina" (1898).

## Inventor

In his work "Perfecto bombardero," published in 1699, Don Sebastián Fernández de Medrano claimed to have invented a unique and innovative method for constructing the chamber of mortars, introducing what he called the "pear" shape. He considered himself the inventor of this design and believed it to be significantly important.
The Sargent General of Battle, Don Sebastián Fernández de Medrano, director of the Royal Military and Mathematics Academy of the Low Countries in Brussels, introduced his own variation of the proportional method in fortification in order to enhance the structures balance and defensive capabilities by precisely dividing inner sides and adjusting proportions, especially for pentagons, to improve fire coverage and minimize vulnerabilities, and boost the fort's defensive effectiveness and resilience. Medrano's approach split the inner side into five parts, allocating one segment to each demigorge and determining the lines of defense by drawing a line perpendicular from the midpoint of the curtain, measuring half the length of the demigorge.
The bastion boundaries were established along the defense lines at a distance equal to 1 1/10 times the length of the curtain. For pentagonal designs, he divided the half-side into six parts, with the demigorge spanning three parts, and positioned the perpendicular line at the midpoint of the curtain. The bastion's edge was then set at a distance equivalent to 1 1/7 of the curtain's length. He also explained how to use tables or a proportional compass for fortification design.

## Euclids Elements

In his textbook "The first six books, eleven, and twelve, of the Geometric Elements of the famous philosopher Euclid of Megara," (1701) Medrano expands on Euclid's propositions, such as the conditions for congruence of triangles, stating, "Si dos triangulos tienen los dos lados del uno, iguales a los dos del otro, cada uno a suyo, y los angulos comprendidos entre estos lados fueren iguales: el tercer lado será igual al tercero" (If two triangles have two sides of the one equal to two sides of the other, each to its own, and the angles included between these sides are equal, then the third side will be equal to the third). Medrano advanced the pedagogical approach to teaching Euclid's elements.
In 1687, "El Ingeniero" (The Engineer), a book already quite complete in the field of fortification, containing in its second volume the study of Geometry and Trigonometry as necessary for solving a variety of problems related to the drawing of plans and calculations for the construction of fortifications.

## Royal Academies of Barcelona, Oran and Cueta

Sebastian's academy had a significant legacy and impact on the formation and progress of the Royal Military Academy of Mathematics in Barcelona during the 18th century. In the late 17th century, plans were made to move the Royal and Military Academy of Mathematics from Madrid to Barcelona. Sebastián Fernández de Medrano was appointed as the general director of the academy.

### The Royal and Military Academy of Mathematics of Barcelona

After deciding to establish the Royal and Military Academy of Mathematics of Barcelona, the council of war sought guidance from Sebastián Fernández de Medrano on how he had structured his academy in Brussels, intending to replicate it in Barcelona. Unfortunately, Medrano died in 1705. Before his death, he had developed an outline for the future Academy of Mathematics in Barcelona, which he submitted to the king. Consequently, the establishment of the Royal Military Academy of Mathematics in Barcelona was authorized by a Royal Decree from King Charles II on January 22, 1700.
The Royal and Military Academy of Mathematics of Barcelona was established following Medrano's model, and on January 22, 1700, a royal decree was issued to start the academy. On August 12, 1701, the implementation of Medrano's guidelines was officially ordered for the Barcelona Academy. Medrano's academic outline was published in a document titled "Formula with which the Sergeant General of Battle, D. Sebastián Fernández de Medrano, established by order of His Majesty the new and Royal Military Academy of which he is the Director." This occurred on January 22, 1700, the same day His Majesty issued a decree to establish the Military Academy in Barcelona and instructed that notices be posted in the War Secretariat to recruit teachers.

## Books

After Medrano's death and after the States of Flanders were no longer part of the Spanish domains, several editions of his works were published in 1708, 1709, 1728, and 1735. Henrico and Cornelio Verdussen, publishers in Antwerp, printed these works using the privilege transferred to them by Lamberto Marchant of Bruges, which had been renewed and confirmed by Philip V in 1708. Additionally, some of the works published in Antwerp during the Austrian domination were dedicated to Philip V himself.
Sebastián Fernández de Medrano's books focus on geometry, artillery practice, engineering, architecture, geography, and exploration. A chronological list of Sebastián Fernández de Medrano's academic books:
* "New invention and method of squaring the circle, not by reason of the diameter to the circumference, but by known parts within the same circle" by Sebastian Fernandez de Medrano 1676. Dedicated to Don Carlos de Aragón de Gurrea, 9th Duke of Villahermosa and published in Brussels by Juan Dandijn
* "Rudimentos geométricos y militares, que propone al estudio y aplicación de los Profesores de la milicia" (Geometric and Military Rudiments, Proposed for the Study and Application of Military Professors) - Published in Brussels under the patronage of the Duke of Villahermosa, 1677.
* "El práctico Artillero" (The Practical Artilleryman) - First published in Brussels, 1680. - The work was reprinted multiple times and inspired the subsequent publication.
* "The engineer: first part, of modern military architercture. Divided into two volumes, which contain five books; the first deals with Regular and Irregular Fortification, and the views of the main authors who wrote about it. The second, on the Speculation of each of its Parts. The third on the Construction of Walls, and their Materials. The fourth on the Site, and Defense of a Fortress. And the fifth, which is the second volume, on Practical Geometry, Trigonometry, and the use of the Rule of Proportion." Published in Brussels in 1687, dedicated to Francisco Antonio de Agurto, 1st Marquess of Gastañaga.
* "The Perfect Architect in Military Art" - A corrected reprint of "The Engineer" from 1687, published in Brussels, 1700 and dedicated to the Duke of Medinaceli. There is a reprint from 1738. There is also a reprint from the year 2000.
* "Breve descripción del mundo, ó guia geographica de Medrano" (Brief Description of the World, or Geographical Guide of Medrano) - Published in Brussels by Lamberto Marchant in 1688 and dedicated to Charles II of Spain and the Marquess of Jodar. A second copy exists that was translated into french in the same year by Jean Leonard and dedicated to the 1st Marquess de Gastanaga, Francisco Antonio de Agurto Salcedo Medrano. A third edition was made and dedicated to King Philip V of Spain, published in 1702.
* "New Description of the World, and Its Parts, Divided Into Three Books" Published in Brussels in 1690 and dedicated to the Marquess of Gastanaga.
* "El Perfecto bombardero y práctico artificial" (The Perfect Bombardier and Practical Artificial) - Dedicated to the Marquess of Bedmar and published in Brussels, 1691.
* "El Ingeniero práctico" (The Practical Engineer) - Available in Brussels since 1696. Dedicated to Maximilian II Emanuel, Prince Elector of Bavaria
* "Elements of Euclid Amplified" - Published in Brussels, date unspecified.
* "Account of a country that has recently been discovered in North America, larger than Europe, and which is brought to light in Spanish by the Sergeant General of Battle..." - Published in Brussels, 1699. Dedicated to Juan de Dios de Silva y Mendoza y Haro, 10th Duke of the Infantado.
* "Brief Treatise on Geography divided into three parts: The first contains the Description of the River and Empire of the American Amazons, with its Geographical Chart: The second what the French and English possess, etc. in the New World, and how they introduce themselves there: And the third about the present state of the Empire of the Great Mughal and the Kingdom of Siam, and brought to light, under the protection of the Most Excellent Count of Fuensalida, by the Battle General Don Sebastian Fernandez de Medrano, Director of the Royal and Military Academy of the Army of the Low Countries." - Dedicated to the Count of Fuensalida and published in Brussels at the House of Lambert Marchant, Bookseller, 1700.
* "The first six books, eleven, and twelve, of the Geometric Elements of the famous philosopher Euclid of Megara" - Published in Antwerp, in 1686, dedicated to the Marquess of Bedmar. A reprint was published in Antwerp in 1728.
* "Brief Description of the World and Its Parts or Geographic and Hydrographic Guide, Divided into Three Books, Composed by Don Sebastian Fernandez de Medrano, Battle General, and Director of the Royal and Military Academy of the Army of the Low Countries" Published in Antwerp by Henrico y Cornelio Verdussen in 1709
* "Foundation and rules of the Academy called La Peregrina." - Publication details unspecified.
* "Infortunios de Alonso Ramirez" - also by Carlos de Sigüenza y Góngora, Pedro Vindel, and Louis Hennepin