January 1, 1366
Annexation of Galicia-Volhynia to Poland
The annexation of Galicia-Volhynia (Ruthenian lands) by Casimir the Great in 1366 was one of the most significant events in medieval Polish history. This strategic move significantly expanded the state's territory, enriched it with new natural resources, and opened new trade routes. This event was the culmination of a long-term process of territorial expansion to the east.
