Mikołaj Radziwiłł was a prominent figure in the history of the Grand Duchy of Lithuania during the 16th century. He belonged to the influential Radziwiłł family, known for their significant political and military roles. Mikołaj served as a military commander and was a key supporter of the Reformation in the region, promoting Protestantism. Radziwiłł was also involved in the political landscape of the Polish-Lithuanian Commonwealth, where he held various titles, including the Grand Hetman of Lithuania. His leadership and alliances helped shape the military and religious dynamics of his time, leaving a lasting impact on the region's history.