Lithuanian Grand Duchy

The Lithuanian Grand Duchy was a powerful medieval state from the 13th to 18th centuries, centered in what is now Lithuania and parts of Poland, Belarus, Latvia, and Russia. It was one of Europe's largest countries during the 15th and 16th centuries, known for its military strength and relative religious tolerance. The Grand Duchy united various Baltic and Slavic peoples under a parliamentary monarchy, playing a significant role in regional politics. It eventually merged with the Polish Kingdom in 1569 through the Union of Lublin, forming the Polish-Lithuanian Commonwealth, which lasted until the late 18th century partitions divided its territory.