The Dukes of Jülich were a noble family that ruled the Duchy of Jülich in present-day Germany from the late Middle Ages until the early modern period. They played a significant role in the politics of the Holy Roman Empire and were involved in various territorial disputes, particularly with neighboring regions like Cleves and Berg. The most notable duke was William the Rich, who expanded the duchy's influence in the 16th century. The dukes were also connected to the House of Habsburg through marriage, which further integrated them into European power dynamics. The duchy eventually became part of the Duchy of Cleves in the 17th century.