Adolph I, Duke of Guelders, was a nobleman who ruled from 1371 to 1423. He was a member of the House of Wassenaer and played a significant role in the politics of the Low Countries. His reign was marked by efforts to strengthen the duchy and expand its territories. During his rule, Adolph I faced various challenges, including conflicts with neighboring regions and internal disputes. He was known for his diplomatic skills and alliances, which helped maintain stability in Guelders. His legacy includes contributions to the development of the region and its governance.