Christian the Younger of Brunswick Christian the Younger ( September 20 , 1599 – June 16 , 1626 ) , Duke of Brunswick - Lüneburg and Bishop of Halberstadt , was a German Protestant military leader during the Thirty Years ' War . During the war , he earned a reputation as a dangerous fanatic . Life . Christian was born in Gröningen ( in today ' s Saxony - Anhalt ) , the third son of Henry Julius , Duke of Brunswick - Lüneburg . After his father ' s death , he was educated by his maternal uncle , King Christian IV of Denmark , and attended the University of Helmstedt . After the death of his brother , Rudolf , Bishop of Halberstadt , in 1616 , he was elected his successor as Lutheran administrator of the Prince - Bishopric of Halberstadt . This position provided him the necessary finances to start a military career . In 1621 Christian joined the army of Maurice of Orange and fought in the Netherlands against a Spanish army . Later he raised his own army and , in liege to Frederick V , Elector Palatine , he carried out three significant battles : the Battle of Höchst ( 1622 ) , the Battle of Fleurus ( 1622 ) , and lastly at the Battle of Stadtlohn ( 1623 ) . He participated in a number of plunderings and burnings along the France - Germany border and throughout the Netherlands . Christian fought alongside the Count of Mansfeld in the first two engagements , and suffered two losses to the Count of Tilly : an arguable one at Höchst , and his final one at Stadtlohn . Christian ' s major success was at Fleurus , where his actions directly led to the relieving of the Protestant stronghold of Bergen op Zoom . A lover of cavalry warfare , Christian gained a reputation for cruelty and violence , especially against the Catholic church . His Catholic opponents dubbed him " der Tolle " ( " the mad " ) due to his excesses in war . This has been disputed and considered by some to be undeserved as it was probably started by pro - Imperial pamphlets at the time . Christian died childless of wounds sustained in battle in 1626 . Campaigns of 1622 - 23 . In 1621 , Christian was one of the few men to continue rallying behind Frederick V , who had only the year before claimed and been deposed from the throne of Bohemia following his crushing loss at the Battle of White Mountain . Frederick was still leader of the Protestant resistance rooted from the 1618 crushed Bohemian Revolution . What attracted Christian to the cause is arguable , but something that may have had to do with it was the fact that before his campaigning , Christian declared a chivalric love for Elizabeth , Frederick ' s wife and daughter of James I of England , who at this point of the war had sent several thousand troops under Sir Horace Vere to the Palatinate . By the end of 1621 he had managed to raise 10 , 000 troops , with whom he wintered in Westphalia , gathering a great treasure from the dioceses of Münster and Paderborn . Christian ' s military actions began in 1622 when Ernst von Mansfeld began organizing his forces and expressed interest in linking up with his army , especially after his ally Georg Friedrich , Margrave of Baden - Durlach , was crushingly defeated at the Battle of Wimpfen . They were caught at the Battle of Höchst , June 22 , 1622 , and although Christian was arguably defeated , he was able to escape with much of his army despite crossing a river under heavy fire and losing all of his baggage . The newly united Protestant army moved into Alsace , leaving Heidelberg , the capital of the Palatinate , to fall to Count von Tilly in September 1622 , effectively forcing Frederick V out of the war . After intense foraging and ravaging of the Alsace region , Christian and Mansfeld moved north in Lorraine , and upon the news of the Spanish siege of Bergen op Zoom , they marched to the relief of the city , fighting the Battle of Fleurus ( August 29 , 1622 ) and in the midst of the battle , Christian displayed his well - known courage and stubbornness on the field by leading four unsuccessful cavalry charges against the Spanish lines under Fernández de Córdoba . It was on the fifth charge that the Protestant horsemen broke the Spanish lines and paved the way for the Protestant relief of Bergen op Zoom that October . This came at a cost of most of Christian ' s infantry and one of Christian ' s arms . Fresh from that victory , Christian spent the winter of 1622 - 23 in the Spanish Netherlands resting and replenishing his army to what would be in spring 1623 set at roughly 15 , 000 . Spring 1623 saw a plan between Christian , Mansfeld , the Hungarian general Bethlen Gabor , and his ally Count Thurn to retake Bohemia for the Protestants and to breathe new life into the ailing Protestant cause . The campaign faltered from the start as Count von Tilly received news of the troop movements and positioned himself in Lower Saxony , with reports from Mansfeld coming to Christian that he did not have the money to pay his armies or to campaign , leaving Christian to himself in the north . Outnumbered again , and leading an army that was not as disciplined as Tilly ' s , Christian made a break for the relative safety of the United Provinces . He was outrun and outmaneuvered 10 miles short of the Dutch border , and in a stand typical of Christian ' s bravery , he was nonetheless decisively defeated at the Battle of Stadtlohn on August 6 , 1623 , when he lost all but 2 , 000 of this 15 , 000 - man army . Broken , he fled for The Hague with the remnants of his army . Defeat and death . Christian ' s defeat signalled the " Palatine Phase " of the Thirty Years ' War , and the end of the Protestant rebellion as a whole . Three days after Stadtlohn , Frederick V signed an armistice with Ferdinand II , ending the former ' s resistance to what seemed as impending Catholic domination of the Holy Roman Empire . Mansfeld shortly thereafter disbanded his army on the Rhine with the entrance of Denmark , the United Provinces , and England into the war in 1625 . Under a plan that involved Christian , Mansfeld , and Christian IV , King of Denmark , pushing from the United Provinces and from Denmark , Christian found himself with ample financial backing . Ordered to advance on the Rhineland , he undertook this mission but quickly found himself checked by Tilly in Hesse , and opted this time to retreat rather than fight . Ill from the outset of the campaign , he died at Wolfenbüttel on June 16 , 1626 , at the age of 26 .