Editing Władysław II Jagiełło (section)

===Polish–Lithuanian–Teutonic war===
{{Main|Polish–Lithuanian–Teutonic War|Battle of Grunwald}}
[[File:Matejko Battle of Grunwald.jpg|thumb|right|300px|[[Battle of Grunwald]], 1410. Painting by Jan Matejko]]
In December 1408, Władysław and Vytautas held strategic talks in [[Navahrudak Castle]], where they decided to foment a [[Samogitian uprising]] against Teutonic rule to draw German forces away from [[Pomerelia]]. Władysław promised to repay Vytautas for his support by restoring Samogitia to Lithuania in any future peace treaty.<ref name="karwasińska">{{harvnb|Karwasińska|Zakrzewski|1892|p=21}}</ref> The uprising, which began in May 1409, at first provoked little reaction from the Knights, who had not yet consolidated their rule in Samogitia by building castles; but by June their diplomats were busy lobbying Władysław's court at [[Oborniki]], warning his nobles against Polish involvement in a war between Lithuania and the Order.<ref name="Jasienica-106"/> Władysław, however, bypassed his nobles and informed the new Grand Master [[Ulrich von Jungingen]] that if the Knights acted to suppress Samogitia, Poland would intervene. This stung the Order into issuing a declaration of war against Poland on 6 August, which Władysław received on 14 August in [[Nowy Korczyn]].<ref name="Jasienica-106"/>

The castles guarding the northern border were in such bad condition that the Knights easily captured those at Złotoryja, [[Dobrzyń nad Wisłą|Dobrzyń]] and [[Bobrowniki]], the capital of Dobrzyń Land, while German burghers invited them into [[Bydgoszcz]] (German: Bromberg). Władysław arrived on the scene in late September, retook Bydgoszcz within a week, and came to terms with the Order on 8 October. During the winter, the two armies prepared for a major confrontation. Władysław installed a strategic supply depot at [[Płock]] in [[Masovia]] and had a [[pontoon bridge]] constructed and transported north down the [[Vistula]].<ref name="turnbull6"/>

Meanwhile, both sides unleashed diplomatic offensives. The Knights dispatched letters to the monarchs of Europe, preaching their usual crusade against the heathens;<ref name="delbrück"/> Władysław countered with his letters to the monarchs, accusing the Order of planning to conquer the whole world.<ref name="Jasienica-108"/> Such appeals successfully recruited many foreign knights to each side. [[Wenceslaus, King of the Romans|Wenceslas IV of Bohemia]] signed a defensive treaty with the Poles against the Teutonic Order; his brother, [[Sigismund, Holy Roman Emperor|Sigismund of Luxembourg]], allied himself with the Order and declared war against Poland on 12 July, though his Hungarian vassals refused his call to arms.<ref name="Jasienica-110"/>