Although they were defeated, the Teutonic Knights withstood the siege on their capital in Marienburg (Malbork) and suffered only minimal territorial losses in the Peace of Thorn (1411).

However, the Knights never recovered their former power, and the financial burden of war reparations caused internal conflicts and economic decline in their lands.

With support from the Pope and Holy Roman Emperor, the Teutons conquered and converted the Prussians by the 1280s and shifted their attention to the pagan Grand Duchy of Lithuania.

[citation needed] In 1385, Grand Duke Jogaila of Lithuania proposed to marry reigning Queen Jadwiga of Poland in the Union of Kreva.

[2] However the Knights responded by publicly contesting the sincerity of Jogaila's conversion, bringing the charge to a papal court.

Poland also had territorial claims against the Knights in Dobrzyń Land and Danzig (Gdańsk), but the two states were largely at peace since the Treaty of Kalisz (1343).

[3] The conflict was also motivated by trade considerations: the Knights controlled lower reaches of the three largest rivers (Neman, Vistula and Daugava) in Poland and Lithuania.

[6] The Knights burned the castle at Dobrin (Dobrzyń nad Wisłą), captured Bobrowniki after a fourteen-day siege, conquered Bydgoszcz (Bromberg), and sacked several towns.

[12] By December 1409, Jogaila and Vytautas had agreed on a common strategy: their armies would unite into a single massive force and march together towards Marienburg (Malbork), capital of the Teutonic Knights.

[14] To counter this perceived threat, Ulrich von Jungingen concentrated his forces in Schwetz (Świecie), a central location from where troops could respond to an invasion from any direction rather quickly.

[13] The first stage of the Grunwald campaign was gathering all Polish–Lithuanian troops at Czerwinsk, a designated meeting point about 80 km (50 mi) from the Prussian border, where the joint army crossed the Vistula over a floating bridge.

[27] Surrounded and leaderless, the Teutonic Knights began to retreat towards their camp in hopes to organize a defensive wagon fort.

The highest-ranking Teutonic official to escape the battle was Werner von Tettinger, Komtur of Elbing (Elbląg).

Polish historian Paweł Jasienica speculated that this was likely an intentional move by Jagiełło, who together with Vytautas preferred to keep the humbled but not decimated Order in play as to not upset the balance of power between Poland (which would most likely acquire most of the Order possessions if it was totally defeated) and Lithuania; but a lack of primary sources precludes a definitive explanation.

[33] Jogaila, meanwhile, also sent his troops to other Teutonic fortresses, which often surrendered without resistance,[34] including the major cities of Danzig (Gdańsk), Thorn (Toruń), and Elbing (Elbląg).

[36] The Polish and Lithuanian besiegers of Marienburg were not prepared for a long-term engagement, suffering from lack of ammunition, low morale, and an epidemic of dysentery.

[37] The Knights appealed to their allies for help and Sigismund of Hungary, Wenceslaus, King of the Romans, and the Livonian Order promised financial aid and reinforcements.

[42] The Grand Masters then needed to rely on mercenary troops, which proved an expensive drain on their already depleted budget.

The internal conflicts, economic decline and tax increases led to unrest and the foundation of the Prussian Confederation, or Alliance against Lordship, in 1441.