Sigismund Korybut Sigismund Korybut ( ; ; ; ; , 1395 – 1435 near Pabaiskas ) was a duke from the Gediminid dynasty , best known as a military commander of the Hussite army and a governor of Bohemia and Prague during the Hussite Wars . Sigismund was most likely born in Novhorod - Siverskyi to Dymitr Korybut , son of Algirdas , Grand Duke of Lithuania , and Anastasia , daughter of Grand Prince Oleg of Ryazan , and raised in the court of his uncle Jogaila ( Władysław Jagiełło ) in Kraków since 1404 . Sigismund was rumored to be expected to become his successor on the Polish throne . Being just an adolescent , he commanded his own banner of the Army of the Crown in the victorious Battle of Grunwald in 1410 . His elder sister , Olena ( Helena ) had been married to an important magnate of Bohemian kingdom , duke Jan of Opava and Ratiborz . Biography . As a regent of Bohemia for Grand Duke of Lithuania Vytautas , he was commissioned to lead his army to Bohemia in April 1422 . The army of Sigismund of Hungary retreated to Hungary in avoidance of the encounter . Sigismund Korybut arrived in Prague on 16 May 1422 , and was acknowledged ruler of Bohemia . He became commander of local Hussites , and fought in Hussite internal disputes . Pope Martin V insisted that Vytautas and Jogaila recall Sigismund from Bohemia . On 24 December 1423 , under Jogaila ' s agreement with Sigismund of Hungary , Sigismund Korybut left Prague with his army . However , he could not refuse an offer of the Bohemian throne and on 29 June 1424 he once again came to Prague with 1 , 500 - strong army , this time without Vytautas ' and Jogaila ' s consent ; their primary objective had been a successful implementation of the Treaty of Melno , thus a conflict with Sigismund of Hungary was undesirable . Therefore , Jogaila ordered a confiscation of Sigismund ' s estates , and the Papal legate excommunicated him . Meanwhile , as a governor of Prague , he dismissed the city ' s council , summoned a new one and succeed in ending the internal discords between Jan Žižka and the Utraquist s , enabling a successful Hussite military campaign to Moravia against Emperor Sigismund . After Žižka ' s death , he became a supreme commander of his army , leading it to victory in the Battle of Usti nad Labem on 16 June 1426 . Sigismund Korybut began negotiations with Sigismund of Hungary , with an intention to reconcile the Catholics and Hussites . However , his political career came to an end in 1427 , when by the initiative of suspicious Prague Taborites , he was imprisoned in Valdštejn Castle for the organization of a revolt in Prague . After release from prison in 1428 , Sigismund participated in Taborite battles in Silesia . The decisive loss in the Battle of Lipany forced him to return to the Grand Duchy of Lithuania . Sigismund Korybut was among the commanders in the Battle of Pabaiskas on the side of his uncle Švitrigaila on 1 September 1435 . His army was decisively defeated by Sigismund Kęstutaitis ' forces . Sigismund Korybut was wounded during the battle , however he fought till the end . According to Jan Długosz , the cause of his death was severe infection of his wounds ( " extremo mortis horrendae supplicio " ) .