William IV, Duke of Julich-Berg was a nobleman who ruled in the late 16th and early 17th centuries. He was born in 1560 and became the Duke in 1592. His reign was marked by efforts to strengthen his territories in the Duchy of Jülich and Duchy of Berg, which were located in present-day Germany. William IV was known for his political maneuvering during a time of religious conflict in Europe. He sought to maintain peace and stability in his duchies while navigating the complexities of the Thirty Years' War. He died in 1625, leaving a legacy of governance in a turbulent era.