The Jagiellon dynasty was a royal family that ruled over several Central and Eastern European countries from the late 14th to the 16th centuries. It originated with Jogaila, the Grand Duke of Lithuania, who became King of Poland in 1386 through his marriage to Queen Jadwiga. The dynasty played a significant role in the political landscape of Europe, uniting the Kingdom of Poland and the Grand Duchy of Lithuania. The Jagiellons expanded their influence through strategic marriages and alliances, leading to a period of prosperity and cultural flourishing. Notable rulers included Casimir IV and Sigismund I, who strengthened the state and promoted the arts. The dynasty ended in 1572 with the death of Sigismund II, leading to the election of kings in Poland.