The Grand Duchy of Lithuania was a significant European state from the 13th to the 18th centuries. It emerged as a powerful entity in the region, encompassing parts of modern-day Lithuania, Belarus, Ukraine, and Poland. The Grand Duchy played a crucial role in the political and cultural landscape of Eastern Europe, often engaging in alliances and conflicts with neighboring powers. At its height, the Grand Duchy of Lithuania was one of the largest countries in Europe. It was known for its diverse population and religious tolerance, fostering a unique blend of cultures. The Grand Duchy eventually formed a union with the Kingdom of Poland in 1569, leading to the establishment of the Polish-Lithuanian Commonwealth.