The Treaty of Christmemel (Lithuanian: Skirsnemunės sutartis) was a treaty signed on 19 June 1431 between Paul von Rusdorf, Grand Master the Teutonic Knights, and Švitrigaila, Grand Duke of Lithuania. Švitrigaila was preparing for a war with Poland to defend his claim to the Lithuanian throne and sought allies. The treaty established an anti-Polish alliance and prompted the Knights to invade the Kingdom of Poland, starting the Polish–Teutonic War (1431–35). Lithuania also surrendered Palanga and three miles of the coastline on the Baltic Sea, thus modifying the Treaty of Melno of 1422.[1]