Siege of Medvėgalis The Siege of Medvėgalis was a brief siege of the Medvėgalis in Samogitia in February 1329 by the Teutonic Knights and King John of Bohemia . The fortress surrendered and the defenders were baptized in the Catholic rite . However , as soon as the Teutonic army returned to Prussia , the Lithuanians returned to their old ways . Background . Medvėgalis was one of the strongest and most important Lithuanian fortresses in Samogitia . First mentioned in written sources in 1316 , over the course of its history it was attacked about 20 times by the Teutonic Knights . After the victorious Battle of Medininkai in 1320 , Lithuania concluded a truce with the Knights . The Teutons resumed military incursions into Lithuania in 1328 . On January 1 , 1329 , King John of Bohemia arrived to Toruń wishing to engage in the holy crusade against pagan Grand Duchy of Lithuania . Back in 1325 he promised Pope John XXII to launch another crusade and received a permission to collect papal income tax for three years to finance the crusade . He brought many noblemen , including Walter VI , Count of Brienne , and Bolesław III the Generous with his brothers , and soldiers from Silesia , Germany , England . The king also brought poet Guillaume de Machaut so that his exploits could be memorialized in poems and songs ( the campaign was described in " Confort d ' ami " written in 1357 ) . According to Peter von Dusburg , the Teutonic army which marched towards Medvėgalis Castle numbered 350 knights and 18 , 000 troops , excluding foot soldiers . Teutonic ambitions were high as parallels were drawn with King Ottokar II of Bohemia and his 1255 campaign which resulted in the conquest of the Sambians . Campaign . According to Jean d ' Outremeuse , the vanguard of the Teutonic army first raided and appropriated livestock of Gelindėnai Hillfort in present - day Plungė district municipality perhaps in an attempt to provoke a pitched battle . Lithuanians , led by Margiris , pursued the robbers and engaged in a battle . However , soon the Teutonic vanguard was joined by the main forces and Lithuanians faced a slaughter . Recognizing King John , who had a reputation for participating in tournaments , Margiris challenged him to a face - to - face duel . King John agreed and they met next morning . However , Margiris ' men attempted to interfere which was strictly against the chivalry rules . Margiris surrendered to John and promised to pay a ransom , which was paid with coins stolen during the 1326 raid into Brandenburg . On 1 February , the Teutonic army surrounded Medvėgalis . After the wooden fortress caught fire , Medvėgalis was captured and defenders were taken captive . Chronicler Wigand of Marburg mentioned that the Grand Master Werner von Orseln wanted to kill them all or at least resettle them in Prussia , but King John insisted that the captives be baptized and allowed to remain in Medvėgalis . About 6 , 000 Lithuanian men , women , and children were baptized in the Roman Catholic rite . According to Machaut , the Teutons also captured four other fortresses – Šiauduva ( localization is debated ) , Gediminas Castle ( localized in Kvėdarna ) , Gegužė , and Aukaimis ( Xedeytain , Gedemine , Geguse , Aukaham ) . Aftermath . At the same time King Władysław I of Poland , who was allied with Grand Duke of Lithuania Gediminas , took advantage of the fact that the main Teutonic force was in Lithuania and attacked Chełmno Land ( Kulmerland ) . Plans for a further military campaign in Samogitia were scrapped and the Teutonic army returned home to deal with the war with Poland . The entire campaign in Lithuania lasted a little more than a week . Once the main army left , the Lithuanians rebelled , retook their fortress , and returned to their pagan beliefs . King John returned to Prussia to crusade against Lithuania twice , in 1337 and 1345 . The siege was fictionalized by Lithuanian writer Antanas Vienuolis in 1956 .