Samogitian uprisings refer to two uprisings by the
Samogitians against the
Teutonic Knights in 1401–1404 and 1409. Samogitia was granted to the Teutonic Knights by
Vytautas the Great,
Grand Duke of Lithuania, several times in order to enlist Knights' support for his other military affairs. The local population resisted Teutonic rule and asked Vytautas to protect them. The first uprising was unsuccessful and Vytautas had to reconfirm his previous promises to transfer Samogitia in the
Peace of Raciaz. The second uprising provoked the Knights to declare war on Poland. Hostilities escalated and resulted in the
Battle of Grunwald (1410), one of the biggest battles of medieval Europe. The Knights were soundly defeated by the joint Polish–Lithuanian forces, but Vytautas and
Jogaila, King of Poland, were unable to capitalize on their victory. Conflicts regarding Samogitia, both diplomatic and military, dragged until the
Treaty of Melno (1422).