The Livonian War (1558-1583) was a conflict in the region of Livonia, which is now part of Latvia and Estonia. It involved several powers, including the Tsardom of Russia, the Kingdom of Poland, the Grand Duchy of Lithuania, and the Swedish Empire. The war began when Ivan IV of Russia sought to expand his territory and influence in the Baltic region. The war resulted in significant territorial changes and the decline of the Livonian Order, a military order that had controlled much of the area. Ultimately, the conflict ended with the Treaty of Kėdainiai in 1583, which established new borders and marked the rise of Poland-Lithuania as a dominant power in the region.