William III of Jülich was a nobleman from the House of Jülich, a prominent family in the Holy Roman Empire. He was born in the late 15th century and became the Duke of Jülich and Berg in 1511. His reign was marked by efforts to strengthen his territories and navigate the complex political landscape of the time. William III was known for his alliances and conflicts with neighboring states, particularly Cleves and Burgundy. His leadership contributed to the cultural and economic development of his duchies, leaving a lasting impact on the region's history.