Title: Grand Inquisitor
Content:  Grand Inquisitor (Inquisitor Generalis, literally Inquisitor General or General Inquisitor) was the lead official of the Inquisition. The title usually refers to the chief inquisitor of the Spanish Inquisition, even after the reunification of the inquisitions. Secretaries-general of the Roman Inquisition were often styled as Grand Inquisitor but the role and functions were different. The Portuguese Inquisition was headed by a Grand Inquisitor, or General Inquisitor, named by the Pope but selected by the king, always from within the royal family. The most famous Inquisitor General was the Spanish Dominican Tomás de Torquemada, who spearheaded the Spanish Inquisition.
Title: Spanish Inquisition
Content:  The Tribunal of the Holy Office of the Inquisition (Tribunal del Santo Oficio de la Inquisición), commonly known as the Spanish Inquisition (Inquisición española), was established in 1478 by the Catholic Monarchs, King Ferdinand II of Aragon and Queen Isabella I of Castile. It was intended to maintain Catholic orthodoxy in their kingdoms and to replace the Medieval Inquisition, which was under Papal control. It became the most substantive of the three different manifestations of the wider Catholic Inquisition along with the Roman Inquisition and Portuguese Inquisition. The "Spanish Inquisition" may be defined broadly as operating in Spain and in all Spanish colonies and territories, which included the Canary Islands, the Kingdom of Naples, and all Spanish possessions in North, Central, and South America. According to modern 
Title: Ars Magica (novel)
Content:  The Pope Gregory IX founded the inquisition courts in 1231. Dominicans and Franciscans were in charge of the organisation, conceived to maintain under control those who refused to live under the Catholic Church's rule. Unlike in other countries the Spanish Inquisition wasn't submitted to the direct authority of Rome. Rather than that it was ruled by a general inquisitor, designated by the King of Spain. This way the Spanish Inquisition became one of the organs of the state, serving it, and the clerics who directed this organ were also public servants. So the Spanish Inquisition didn't apply punishments, but decided about the punishment that the regular civil authority usually had to apply.
Title: Spanish Inquisition
Content:  a tool to control the power of the Roman Church in Spain. The Spanish Inquisition was unique at the time because it did not depend on the Pope in the slightest. Once the bull of creation was granted, the head of the Inquisition was the Monarch of Spain. It was in charge of enforcing the laws of the king regarding religion and other private-life matters, not of following orders from Rome, from which it was independent. This independence allowed the Inquisition to investigate, prosecute and convict clergy for both corruptions (pedophilia, forgery of documents, etc.) and possible charges of treason of conspiracy against the crown (on the Pope's behalf presumably) 
Title: History of the Jews in Europe
Content:   The Spanish Inquisition was established in 1478 by Catholic Monarchs Ferdinand and Isabella to maintain Catholic orthodoxy in their kingdoms and was under the direct control of the Spanish monarchy. It was not definitively abolished until 1834, during the reign of Isabel II. The Inquisition, as an ecclesiastical tribunal, had jurisdiction only over baptized Christians. However, since Jews (in 1492) and Muslim Moors (in 1502) had been banished from Spain, jurisdiction of the Inquisition during a large part of its history extended in practice to all royal subjects. The Inquisition worked in large part to ensure the orthodoxy of recent converts known as conversos or marranos.
Title: Spanish Inquisition
Content:  Fray Alonso de Ojeda, a Dominican friar from Seville, convinced Queen Isabella of the existence of Crypto-Judaism among Andalusian conversos during her stay in Seville between 1477 and 1478. A report, produced by Pedro González de Mendoza, Archbishop of Seville, and by the Segovian Dominican Tomás de Torquemada – of converso family himself – corroborated this assertion. Spanish monarchs Ferdinand and Isabella requested a papal bull establishing an inquisition in Spain in 1478. Pope Sixtus IV granted a bull permitting the monarchs to select and appoint two or three priests over forty years of age to act as inquisitors. In 1483, Ferdinand and Isabella established a state council to administer 
Title: History of the Catholic Church in Spain
Content:   After centuries of the Reconquista, in which Christian Spaniards fought to drive out the Moors, the Spanish Inquisition was established in 1478 by Catholic Monarchs Ferdinand II of Aragon and Isabella I of Castile, to complete the religious purification of the Iberian Peninsula. It was intended to maintain Catholic orthodoxy in their kingdoms, and to replace the medieval inquisition which had been under papal control. The new body was under the direct control of the Spanish monarchy. The Inquisition, as an ecclesiastical tribunal, had jurisdiction only over baptized Christians, some of whom also practised other forms of faith and at the time were considered heretics according to the Catholic Church and recently formed kingdoms at the time. The Inquisition worked in large part to ensure the orthodoxy of recent converts. In the centuries that followed Spain saw itself as the bulwark of Catholicism and doctrinal purity.
Title: Spanish Inquisition
Content: 1482 In Seville and in Córdoba. ; 1485 In Toledo and in Llerena. ; 1488 In Valladolid and in Murcia. ; 1489 In Cuenca. ; 1505 In Las Palmas (Canary Islands). ; 1512 In Logroño. ; 1526 In Granada. ; 1574 In Santiago de Compostela. Beyond its role in religious affairs, the Inquisition was also an institution at the service of the monarchy. The Inquisitor General, in charge of the Holy Office, was designated by the crown. The Inquisitor General was the only public office whose authority stretched to all the kingdoms of Spain (including the American viceroyalties), except for a brief period (1507–1518) during which there were two Inquisitors General, one in the kingdom of Castile, and the other in Aragon.  The 
Title: Mexican Inquisition
Content:  The Mexican Inquisition was an extension of what had been going on in Spain and the rest of Europe for some time. Spanish Catholicism had been reformed under the reign of Isabella I of Castile (1479– 1504), which reaffirmed medieval doctrines and tightened discipline and practice. She also introduced the Holy Office of the Inquisition in 1478 with the permission of Pope Sixtus IV, combining secular and religious authority. Much of the zeal to reaffirm traditional Catholic tenets came from the history of the Reconquista. Those who overthrew Muslim domination of the peninsula were very committed to the goal of making Catholicism completely dominant wherever they could. After the discovery and conquest of the New World, the effort to spread the faith included the belief that non-Christians would benefit from instruction in the "true faith."
Title: Tomás de Torquemada
Content:  Torquemada deeply feared the Marrano and Morisco as a menace to Spain's welfare by both their increasing religious influence and their economic domination of Spain. The Crown of Aragon had Dominican inquisitors almost continuously throughout much of the 14th and the 15th centuries. King Ferdinand and Queen Isabella petitioned Pope Sixtus IV to grant their request for a Holy Office to administer an inquisition in Spain. The Pope granted their request and established the Holy Office for the Propagation of the Faith in late 1478. The papal bull gave the sovereigns full powers to name inquisitors. Rome retained the right to formally appoint the royal nominees. Henry Charles Lea observed that the Spanish Inquisition in both Castile and Aragon remained firmly under Ferdinand's direction throughout the joint reign.

Question: who was the head of the spanish inquisition?
Answer: Grand Inquisitor.
Tomás de Torquemada.
Dominican Tomás de Torquemada.