Union of Krewo

The Union of Krewo, established in 1385, was a formal agreement between the Kingdom of Poland and the Grand Duchy of Lithuania. It aimed to strengthen both territories against common threats, particularly from the Teutonic Order. This personal union meant that both regions would share the same monarch, specifically Queen Jadwiga of Poland and Grand Duke Władysław II Jagiełło of Lithuania, uniting their crowns. Despite their distinct laws and cultures, this alliance paved the way for significant political, economic, and military cooperation, ultimately leading to the formation of a larger Polish-Lithuanian Commonwealth.