Siege of Godesberg The Siege of Godesberg , 18 November – 17 December 1583 , was the first major siege of the Cologne War ( 1583 – 1589 ) . Seeking to wrest control of an important fortification , Bavarian and mercenary soldiers surrounded the Godesberg ( " " Wotan ' s Mountain " " ) , and the village then of the same name , now Bad Godesberg ( " " Wotan ' s Mountain Spa " " ) , located at its foot . On top of the mountain sat a formidable fortress , similarly named Godesburg ( " " Wotan ' s Castle " " ) , built in the early 13th century during a contest over the election of two competing archbishops . Towering over the Rhine valley , the Godesburg ' s strategic position commanded the roads leading to and from Bonn , the Elector of Cologne ' s capital city , and Cologne , the region ' s economic powerhouse . Over time , the Electors strengthened its walls and heightened its towers . They added a small residence in the 14th century and the " donjon " ( also called a " Bergfried " or keep ) developed as a stronghold of the Electoral archives and valuables . By the mid - 16th century , the Godesburg was considered nearly impregnable and had become a symbol of the dual power of the Prince - electors and Archbishops of Cologne , one of the wealthiest ecclesiastical territories in the Holy Roman Empire . The Cologne War , a feud between the Protestant Elector , Gebhard , Truchsess of Waldburg , and the Catholic Elector , Ernst of Bavaria , was yet another schismatic episode in the Electoral and archdiocesan history . The Godesburg came under attack from Bavarian forces in November 1583 . It resisted a lengthy cannonade by the attacking army ; finally , sapper s tunneled into the basalt core of the mountain , placed of powder into the tunnel and blew up a significant part of the fortifications . The explosion killed many of the defending troops , but the resulting rubble impeded the attackers ' progress , and the remaining defenders continued to offer staunch resistance . Only when some of the attackers entered the castle ' s inner courtyard through the latrine system were the Bavarians able to overcome their opponents . The Godesburg ' s commander and a number of surviving defenders took refuge in the keep ; using prisoners held in the dungeons as hostages , the commander negotiated safe passage for himself , his wife and his lieutenant . The others who were left in the keep — men , women and children — were killed . Nearby Bonn fell to the Bavarians the following month . Background . The Cologne War , 1583 – 1589 , was triggered by the 1582 conversion of the Archbishop - Prince Elector of Cologne , Gebhard , Truchsess of Waldburg , to Calvinism , and his subsequent marriage to Agnes of Mansfeld - Eisleben in 1583 . When he refused to relinquish the Electorate , a faction of clerics in the Cologne Cathedral chapter elected another archbishop , Ernst of Bavaria , of the House of Wittelsbach . Initially , troops of the competing Archbishops of Cologne fought for control of the Electorate ; within a few months , the local feud between the two parties expanded to include supporters from the Electorate of the Palatinate on the Protestant side , and the Duchy of Bavaria on the Catholic side . Italian mercenaries hired with papal gold augmented the Catholic force . In 1586 , the conflict expanded further , with direct involvement of the Spanish Netherlands for the Catholic side , and tertiary involvement from Henry III of France and Elizabeth I of England on the Protestant side . At its most fundamental , it was a local feud between two competing dynastic interests — the Seneschal s ( " Truchsess " ) of the House of Waldburg and the dukes of the House of Wittelsbach — that acquired religious overtones . The dispute had broad implications in the political , social , and dynastic balance of the Holy Roman Empire . It tested the principle of ecclesiastical reservation established in the religious Peace of Augsburg ( 1555 ) . The 1555 agreement settled religious problems in the Empire with the principle " Cuius regio , eius religio " : the subjects of a secular prince followed the religion of their sovereign . Ecclesiastical reservation excluded the territories of the imperial prelates ( bishops , archbishops , abbots or abbesses ) from " cuius regio , eius religio " . In an ecclesiastical territory , if the prelate changed his religion , his subjects did not have to do so . Instead , the prelate was expected to resign from his post . Problematically , the 1555 agreement did not specify this detail . Controversy of conversion . Agnes of Mansfeld - Eisleben was a Protestant canoness ( meaning that she was a woman living in a religious community , but not bound by a perpetual vow ) at a convent in Gerresheim , today a district of Düsseldorf . After 1579 , she maintained a lengthy liaison with the Archbishop of Cologne , Gebhard of Waldburg - Trauchburg , Truchsess of Waldburg . In defense of her honor , two of her brothers convinced Gebhard to marry her , and Gebhard considered converting to Calvinism for her . Rumors spread throughout the Electorate of his possible conversion , and that he might refuse to relinquish his position . The Electorate had overcome similar problems . Hermann of Wied had converted to Protestantism and resigned in 1547 . Salentin of Isenburg - Grenzau , Gebhard ' s immediate predecessor , had resigned upon his marriage . In December 1582 , Gebhard announced his conversion and extended equal religious rights to Protestants in the Electorate . In February , he married Agnes . At the end of March 1583 , the Pope excommunicated him . The Cathedral chapter promptly elected a new archbishop , Ernst of Bavaria . With two competing archbishops , both claiming the see and the Electorate , the contenders and their supporters gathered the troops . In numbers , Ernst had the advantage . The Pope hired 5 , 000 mercenaries from the Farnese family to support the new Elector . Ernst ' s brother , the Duke of Bavaria , provided an army and Ernst arranged for his brother Ferdinand ' s army to take possession of the so - called " Oberstift " , the southern territory of the Electorate ; his troops plundered many of its villages and towns . With the support of Adolf von Neuenahr and the Count Solms , Gebhard secured some of the northern and eastern portions of the Electorate , where he held a geographical advantage in his proximity to the rebellious Dutch provinces . In the south , however , Ferdinand ' s troops hunted the soldiers Gebhard had left in possession of such " Oberstift " villages as Ahrweiler and Linz ; Gebhard ' s troops were forced out of their strongholds , hunted through the countryside , and eventually captured . By the fall of 1583 , most of the " Oberstift " had fallen to Ferdinand ' s army and many of Gebhard ' s erstwhile supporters — including his own brother — had returned home . In some cases , they honored parole agreements made after their capture . A strong supporter , Johann Casimir of Simmern , brother of the powerful Louis VI , Elector Palatine , returned to the Palatine when his brother died . Other supporters were frustrated by Gebhard ' s chronic inability to pay his troops , or intimidated by threats of Rudolf II , Holy Roman Emperor . By late October 1583 , most of the " Oberstift " had fallen , although he still held the Godesburg , located near the villages of Godesberg and Friesdorf , the formidable fortress at Bonn , and the fortified village of Poppelsdorf . Fortress . The Godesburg foundation stone was laid on 15 October 1210 upon the order of Dietrich of Hengebach , the Archbishop of Cologne , who was himself in disputed possession of the Electorate and fighting to keep his position . Although his competitors deposed Dietrich in 1212 , his successors finished and enlarged the fortress ; it featured in chronicles of the subsequent centuries as both a symbolic and physical embodiment of the power of the archbishop of Cologne in his many struggles for regional authority in secular and ecclesiastical matters . Furthermore , by the late 14th century , the fortress had become the repository of the Elector ' s valuables and archives . By the mid - 16th century , with the inclusion of residential facilities , the castle was popularly considered the " Lieblingssitz " , or the favorite seat ( home ) , of the Electors . The fortification originally had been constructed in the medieval style . In the reign of Siegfried II of Westerburg ( 1275 – 1295 ) , it successfully resisted a five - week siege by the Count of Cleves . Successive archbishops continued to improve the defenses with stronger walls , adding levels to the central " Bergfried " , which was cylindrical , not square like many medieval " donjons " . In addition to the construction of the small residence , these archbishops also expanded the inner works to include dungeons and a chapel ; they fortified the walls with towers and crenelation s , added a curtain wall , and improved the roads that led to the entrance in a series of switchbacks . By the 1580s , the Godesburg was not only the favorite residence of the Elector , but also an elaborate stone fortress . Although it retained some of its medieval character , it had been enhanced partially in the style made popular by Italian military architects . The physical location on the mountain did not permit the star - shaped " trace italienne " ; nevertheless , the Godesburg ' s cordons of thick , rounded walls and massive iron - studded gates made its defenders formidable adversaries . Its height , some above the Rhine on the peak of a steep hill , made artillery assault difficult . The approach road , with its hairpin turns , made battering rams impractical . The turns , overlooked by the castle wall , made foot assault dangerous and slow . Defenders could fire down on attackers from many angles . Fortifications such as this , and the star - shaped fortresses more commonly found in the flatter lands of the Dutch Provinces , increasingly made 16th - century warfare both difficult and expensive ; victory was not simply a matter of winning a battle over the enemy ' s army . Victory required traveling from one fortified and armed city to another and investing time and money in one of two outcomes . Ideally , a show of extraordinary force convinced city leaders to surrender . If the show of force did not intimidate a city , the alternative was an expensive siege that reduced the city to rubble and ended with storming the ruins . In the case of the former , when a city capitulated , it would have to quarter troops at its own expense , called " execution " , but the soldiers would not be permitted to plunder . In the case of the latter , no quarter would be given to the defenders and the victorious soldiers were released to pillage , plunder , and sack . Investment of the Godesburg . On 13 – 14 November , Ferdinand of Bavaria ( Ernst ' s brother ) and the Count of Arenberg took the Elector ' s castle at Poppelsdorf ; on 18 November , they moved to attack the Godesburg . This fortress was considerably stronger than the one at Poppelsdorf and of supreme strategic importance for the projected attack on Bonn , the capital city of the Electorate . The Godesburg was defended by Lieutenant Colonel Felix Buchner , Captain of the Guard Eduard Sudermann , a garrison of soldiers from the Netherlands , and a few cannons . Sudermann was a patrician from Cologne , and the son of Cologne ' s " Bürgermeister " ( mayor ) Dr . Heinrich Sudermann ( 1520 – 1591 ) , a jurist and ambassador , and one of the most influential men in the imperial city and throughout the merchant capitals of the northern German states . According to contemporary sources , around 180 people lived in the facility , including a number of peasants , the Dutch soldiers defending it , and an unknown number of women and children . The fortress was also home to several of Gebhard ' s prisoners . The Abbot of Heisterbach , Johann von St . Vith , had been taken prisoner in July 1583 when Sudermann ' s troops sacked a number of villages in the region and plundered the Heisterbach monastery . Other prisoners held in the Godesburg included Gebhard von Bothmer , the suffragan ( auxiliary bishop ) of Hildesheim , and Captain Ranucino from Florence , the captured commander of Deutz , across the Rhine from Cologne . To besiege the fortress , Ferdinand brought more than 400 " Fussvolk " ( foot soldiers ) and five squadrons of mounted soldiers , plus a half dozen heavy caliber cannons , called culverin s . His soldiers , among them Spanish and Italian mercenaries , took up quarters in neighboring villages , a process accompanied by pillage , arson , murder and rape . On 18 November , the first day of the siege , Ferdinand sent a trumpeter and formally asked the fortress to surrender ; the defending garrison replied that they had sworn their allegiance to Gebhard and would fight to the death for him . Cannonade ( 18 – 28 November 1583 ) . In response , Ferdinand took control of the village at the foot of the mountain and encircled the site . He surveyed the locale for two days to identify the most promising angle of attack . The customary equipage of siege warfare — the siege tower , the trebuchet , and the crossbow — would be ineffective . The distance between the curtain wall and the valley floor and the angle of the hill placed the Godesburg out of range . The besiegers had no choice but to use expensive artillery , although the angle would decrease its effectiveness . Ferdinand initially placed three cannons at the foot of the mountain , in Godesberg village . Daily , cannonballs and mortar shells smashed against the castle ' s walls . Nightly , the defenders repaired the damage . At the following sunrise , the assault began anew . Ferdinand ' s cannons were ineffective against the fortification , as were his mortars ; in the course of the cannonade , return fire even managed to destroy a few of his own pieces . From his place of safety in the north , Gebhard understood well the potential of the loss of the Godesburg , yet he was relatively helpless to help his garrison . In an effort to garner financial support from the Protestant states , in November 1583 he wrote to the Archbishop of Canterbury , in London : " Verily , the Roman Antichrist moves every stone to oppress us and our churches . . . " Although financial help from the English was not forthcoming , Ferdinand could not break the defenses . On 28 November , ten days after the beginning of the siege , artillery fire had wasted several thousand pounds of powder in the ineffectual bombardment . Ferdinand moved his cannons to an elevated position in a hillside vineyard to the west of the Godesburg . The height offered a more advantageous trajectory with which to fire on the walls of the Godesburg ' s outer ward . Within a few hours , his cannonade had breached them . Ferdinand sent three Italian experts to examine the breach and to advise him on the next step ; the Italians , having come under fire during their examination , concluded that storming the castle would incur many casualties . The defenders still had the advantage of height and would be able to shoot at attackers from multiple towers and defensive positions inside the walls . Ferdinand decided not to pursue this tactic . Unable to storm the castle , Ferdinand considered two options : abandon the siege , which he could not do , or blow up the fortress . This option of last resort usually made a fortress unusable . Furthermore while he considered his options , the defenders repaired the breaches caused by the cannonade and reinforced the walls , making them even stronger than they had been . The defenders also removed the roof of the St . Michael ' s Chapel in the castle ' s outer ward , filled the chapel with dirt to reinforce its walls , and placed some of their artillery pieces within the walls . Sapping ( completed 16 December 1583 ) . Ferdinand reluctantly ordered saps to be dug into the side of the mountain . The sapping was difficult and dangerous and the sappers worked under continuous attack from the castle ' s defenders , who fired on them with small arms and the castle ' s artillery and dropped rocks and debris on their heads . The forced labor of local peasants minimized losses among Ferdinand ' s own troops , but many of the peasants perished in the effort . On 6 December , the sappers reached the south - eastern side of the fortress ' s outermost wall and then spent another ten days undermining the basalt on which the castle stood ; they completed their work on 16 December and placed of powder into the mine . Ferdinand reported on the siege ' s progress in a letter to his older brother , Duke Wilhelm , dated 15 December 1583 : " The fortress stands on solid rock . . . . [ Y ] esterday we had reached the outer wall of the castle , and in a day or two we hope to send the fortress into the sky . " Destruction of the fortress ( 17 December 1583 ) . On 17 December , Ferdinand again asked the castle ' s defenders to surrender . They replied that they did not know the meaning of the word and would hold the Godesburg to the last man . A newspaper report dated 23 December 1583 relates that , having given Ferdinand a rude reply , the defenders went back to lunch . Ferdinand ordered 400 men to enter the saps ; these men would storm the castle once the mine had been detonated . The remainder of his foot soldiers and cavalry was to wait in the fields below . A number of sources assert that the fuse was lit at around 1 : 00 pm , although the 19th - century local historian Heinrich Joseph Floß argued that these sources are mistaken , and that the explosion clearly occurred in the morning . All sources agree that the explosion , with a dreadful crack , propelled chunks of the towers and walls high into the air . Almost half the Godesburg collapsed instantly . According to a newspaper report dated 13 January 1584 , debris raining on the valley below damaged a number of houses , destroying some of them completely . Amidst the flames and rubble , Arenberg ' s and Ferdinand ' s troops tried to storm the castle , but found their way blocked by masses of debris created by their own explosives . Furthermore , although close to half of the garrison had perished in the explosion and subsequent collapse of the fortifications , those who remained offered staunch resistance by throwing rocks on the approaching attackers , causing a large number of casualties . In frustration , 40 or 50 of the attackers tied together two ladders and crawled through the sluice - ways of the garderobe ( latrines ) that emptied on the hillside , thus gaining access to the interior of the castle . There they killed around 20 of the defenders in fierce fighting ; the remaining defenders , approximately 70 men , among them Buchner and Sudermann , the garrison commander and his lieutenant , sought refuge in the castle ' s keep . In this way , Ferdinand ' s infantry at last gained unopposed access to the fortress . Storming the castle had taken about two hours . Out of options , Buchner opened negotiations , using those interred in the castle as hostages . Presenting them at the keep ' s door , he made clear that they would be killed unless Ferdinand promised to spare his , his wife ' s and Sudermann ' s lives . Ferdinand acceded to Buchner ' s demand ; some sources maintain that the Abbot of Heisterbach , one of the prisoners , had been treated decently by Buchner throughout his imprisonment in the castle and himself asked for Buchner ' s life to be spared . The prisoners were released . With much difficulty , given the state of mind of the besiegers , Ferdinand and Arenberg brought the Buchners and Sudermann out of the castle alive . Once the Buchners , Sudermann , and the hostages were clear of the fortress , Ferdinand released his troops , who were in an ugly mood and hungry for blood and plunder . All those who remained in the keep — soldiers , men , women and children — were killed , some inside the keep , some in the courtyard below ; the slaughter lasted well into the night . The castle ' s 178 dead were buried in two mass graves whose locations remain unknown . Among those who perished in the destruction and storming of the castle was also one of the prisoners , a vicar from Hildesheim . The Hildesheim suffragan , too , was not among the rescued prisoners ; he had died during his incarceration , a short while before the castle was stormed . Gebhard lost an important stronghold in the " Oberstift " and Ernst ' s forces had acquired a ruin . The residence was unusable , and the fortifications were mere rubble . The keep had survived the blast and various armies used it as a watch tower in the Thirty Years ' War . Ernst ' s troops , under his brother ' s command , saturated the region , and the between Godesberg and Bonn bore a greater resemblance to a military camp than to a road . Walloon riders and squadrons of Italian cavalry , paid for by the pope , galloped back and forth . Forty companies of infantry trudged toward Bonn , including Walloons and Bavarians . They looked forward to besieging Bonn , the Elector ' s capital city , to which they laid siege on 21 December 1583 , and which they took on 28 January 1584 . Aftermath . The siege of the Godesburg and its subsequent destruction were a mere taste of things to come . It was the first of many sieges in the Cologne War , and the castle ' s fall eventually led to the fall not just of Bonn , but of several other principal towns and cities in the Electorate of Cologne : Hülchrath , Neuss and Werl . Several smaller fortified towns such as Gelsenkirchen , Unkel and Brühl were also either heavily damaged or destroyed before , during and after the siege . In addition to damage to the towns and cities , Ernst ' s supporters managed to restrict imports and exports to and from the Electorate , not only crippling Gebhard ' s financial resources but resulting in economic hardship for the inhabitants . Advances in military architecture over the previous century had led to the construction or enhancement of fortresses that could withstand the pounding of cannonballs and mortar shells . For both Gebhard and Ernst , winning the war required mobilizing enough men to encircle a seemingly endless array of enemy artillery fortresses . These could be protected with relatively small garrisons , but taking them required both expensive artillery and enough men to storm the battlements . Furthermore , the victor had to maintain and defend all his possessions as they were acquired . Even the ruin of the Godesburg required a garrison and a defensive strategy ; as a strategic point on the north - south road from Bonn to Koblenz , it came under siege in 1586 and again in 1588 . The Cologne War , similar to the Dutch Revolt , was not a war of assembled armies facing each other on a field , but a war of artillery sieges . It required men who could operate the machinery of war , which meant extensive economic resources for soldiers to build and operate the siege works , and a political and military will to keep the machinery of war operating . The destruction of so prominent a fortress was also news . When Frans Hogenberg and Georg Braun compiled their " Civitates Orbis Terrarum " , a collection of important scenes and locales , they included Hogenberg ' s engraving of its destruction as not only an important sight , but an important event ( see Info Box , top ) . Hogenberg lived in Bonn and Cologne in 1583 , and likely saw the site himself . After overwhelming the Godesburg , the Bavarians found a large marble slab in the ruins : the castle ' s foundation stone , which had been displaced by the explosion . The stone is a block of black marble with a Latin inscription commemorating the construction of the fortress by Dietrich I von Hengebach in 1210 : " ANNO · D ( OMI ) NI · M · C · C · X · GUDENSBERG · FUNDATUM · E ( ST ) · A · TEODERICO · EP ( ISCOP ) O · I ( N ) · DIE · MAUROR ( UM ) · M ( A ) R ( TYRUM ) . " A gold inscription was added to the back of the stone , noting that it had been found " on the very top of the blasted wall . " Ferdinand took the stone to Munich , where it was kept in a museum beside a fresco painting in an arcade commemorating the siege . Today , the foundation stone is in the Rheinisches Landesmuseum in Bonn . Long - term consequences . Gebhard ' s eventual defeat changed the balance of power in the Electoral College of the Holy Roman Empire . In 1589 , Ernst of Bavaria became uncontested Prince - elector of Cologne , the first Wittelsbach to hold the position . Wittelsbach authority in northwestern German territories endured until the mid - 18th century , with the election of a succession of Bavarian princes to the archbishop ' s throne and to the Prince - Elector ' s seat . This gave the family two voices in the choice of imperial candidates , which had ramifications in the 18th century . In 1740 , Charles Albert , Duke of Bavaria , laid claim to the imperial title ; his brother Klemens August of Bavaria , then the Archbishop and Prince - elector , cast his vote for Charles and personally crowned him at Frankfurt am Main . The shift of the emperor ' s orb from the House of Habsburg to the Wittelsbach family , albeit a brief event , was only resolved by the ascension of Maximilian III Joseph who , with the Treaty of Füssen , eschewed any imperial pretensions . Gebhard ' s defeat also changed the religious balance in the northwestern states . Although the Peace of Augsburg ( 1555 ) had addressed earlier the problem of religious pluralism , the solution potentially converted simple , and usually local , legal disputes into dynastic and religious warfare , as the Cologne War itself demonstrated . The result of the Cologne War gave the Counter Reformation a foothold in the lower Rhine . Ernst was a product of Jesuit education . Once his position was secured , he invited Jesuits into the territory to help re - establish Catholicism , a task which the Order approached zealously . They ejected Protestant pastors from parishes , sometimes by force , and re - established catechism education and pastoral visitations . Even when communities appeared to be reconverted , the Jesuits maintained strict supervision to identify recalcitrant Protestants or backsliders . The Jesuit reintroduction of Catholicism postponed the solution of Germany ' s religious problems for another half century . Finally , the German tradition of local and regional autonomy created structural and cultural differences in the Holy Roman Empire , compared to the increasingly centralized authority of such other European states as France , England , and Spain . The unabashed intervention of Spanish , French , Italian , Dutch , English and Scots mercenaries in the war , as well as the influence of papal gold , changed the dynamic of internal German confessional and dynastic disputes . The great " players " of the Early Modern European political stage realized that they could enhance their own positions " vis - a - vis " one another by assisting , promoting or undermining local and regional competition among the German princes , as they did in the feud between Gebhard and Ernst . Conversely , German princes , dukes , and counts realized that they could acquire an edge over their competitors by promoting the interests of powerful neighbors . The scale of involvement of such external mercenary armies as Spain ' s Army of Flanders set a precedent that internationalized contests of local autonomy and religious issues in the German states , a problem not settled until the Peace of Westphalia in 1648 . Despite that settlement , German states remained vulnerable to both external intervention and religious division , as they were in the Cologne War .