William I of Jülich was a nobleman who ruled the Duchy of Jülich in the late 15th century. He was born around 1455 and became Duke in 1511. His reign was marked by efforts to strengthen the duchy's political and economic position in the region. William was also known for his involvement in the broader political landscape of the Holy Roman Empire. He was related to several influential families, including the House of Cleves, which played a significant role in the politics of Northern Europe during his time. His legacy includes contributions to the development of Jülich as a center of power.