Duke Eric IV of Schleswig was a nobleman who ruled during the late 14th century. He was part of the House of Schauenburg and held the title of Duke of Schleswig from 1375 until his death in 1412. His reign was marked by efforts to strengthen the duchy and manage its relationships with neighboring territories. Eric IV was also known for his involvement in the political dynamics of Denmark and Germany. He played a significant role in the regional conflicts of the time, navigating alliances and rivalries that shaped the history of Northern Europe. His legacy is tied to the complex feudal system of the era.