Siege of Marienburg ( 1410 ) The Siege of Marienburg was an unsuccessful two - month siege of the castle in Marienburg ( Malbork ) , the capital of the monastic state of the Teutonic Knights . The joint Polish and Lithuanian forces , under command of King Władysław II Jagiełło and Grand Duke Vytautas , besieged the castle between 26 July and 19 September 1410 in a bid of complete conquest of Prussia after the great victory in the Battle of Grunwald ( Tannenberg ) . However , the castle withstood the siege and the Knights conceded only to minor territorial losses in the Peace of Thorn ( 1411 ) . Marienburg defender Heinrich von Plauen is credited as the savior of the Knights from complete annihilation . Background . Allied Polish and Lithuanian forces invaded Prussia in July 1410 with a goal of capturing Marienburg . Their path was blocked by the Teutonic Knights , who engaged the allied forces in the decisive Battle of Grunwald on 15 July 1410 . The Knights suffered a great defeat , leaving most of their leadership dead or captured . The victorious Polish and Lithuanian forces stayed on the battlefield for three days ; during this time Heinrich von Plauen , Komtur of Schwetz ( Świecie ) , organized defense of Marienburg . Von Plauen did not participate in the battle and was trusted to command reserve forces of about 3 , 000 men in Schwetz . It is not entirely clear whether von Plauen marched to Marienburg based on pre - battle instructions of Grand Master Ulrich von Jungingen or on his own initiative to fill the leadership void . As the Polish – Lithuanian forces moved on to Marienburg , three Teutonic fortresses – Hohenstein ( Olsztynek ) , Osterode ( Ostróda ) , and Christburg ( Dzierzgoń ) – surrendered without resistance . The allied forces moved slowly , averaging only about per day , giving time for von Plauen to organize the defense . This delay has been criticized by modern historians as one of the greatest Polish – Lithuanian tactical mistakes and has been a subject of much speculation . Siege . The main Polish – Lithuanian forces arrived only on 26 July 1410 . The day before von Plauen ordered the town outside the Marienburg Castle to be burned , depriving allied soldiers of shelter and clearing the battlefield . The siege was not intense : Polish King Jogaila was confident that Prussia had already fallen and began distributing land among his nobles . He sent his troops to capture numerous small castles that were left without garrisons . Only eight castles remained in Teutonic hands . The Knights were allowed to communicate with their allies . They send envoys to Sigismund of Hungary and Wenceslaus , King of the Romans , who provided a loan to hire mercenaries and promised to send Bohemian and Moravian reinforcements by the end of September . The Livonian Order sent 500 men as soon as its three - month truce with Lithuania expired . The siege , holding Jogaila ' s army in place , helped to organize defensive forces in other parts of Prussia . The besiegers expected capitulation and were not prepared for a long - term engagement , suffering from lack of ammunition , low morale , and an epidemic of dysentery . The nobles wanted to return home for the harvest and the mercenaries wanted to get paid . Lithuanian troops , commanded by Vytautas , were the first to withdraw . The siege was eventually lifted on 19 September . Before departing , Jogaila built a stronghold in Stuhm ( Sztum ) , south of Marienburg , hoping to keep pressure on the Knights . The Polish – Lithuanian forces returned to Poland and Lithuania , leaving Polish garrisons in fortresses that surrendered or were captured . Aftermath . After the withdrawal of the Polish – Lithuanian forces , the Knights started taking back their fortresses . By the end of October , only four Teutonic castles remained in Polish hands – border towns of Thorn ( Toruń ) , Nessau ( Nieszawa ) , Rehden ( Radzyń Chełmiński ) and Strasburg ( Brodnica ) . Jogaila raised a fresh army and dealt another defeat to the Knights in the Battle of Koronowo on 10 October 1410 . Von Plauen , using his reputation as hero of Marienburg , was selected as the new Grand Master in November . Von Plauen wanted to continue warfare , but he was pressured by his advisers into peace negotiations . The Peace of Thorn was signed on 1 February 1411 . It is considered a diplomatic victory for the Knights as they suffered only minimal territorial losses . The Siege of Marienburg and subsequent Peace of Thorn are seen as disappointing results of the great Battle of Grunwald . The Marienburg Castle was captured by Poles during the Thirteen Years ' War ( 1454 – 66 ) .