William I, Duke of Julich-Berg, was a nobleman who ruled in the late 15th and early 16th centuries. He was born in 1467 and became Duke in 1511, overseeing the territories of Julich and Berg in present-day Germany. His reign was marked by efforts to strengthen his duchy and navigate the complex political landscape of the Holy Roman Empire. William I was also known for his involvement in the Habsburg succession disputes, which influenced regional power dynamics. He died in 1539, leaving a legacy that included the promotion of trade and alliances that would shape the future of his duchy and surrounding areas.