Eric IV of Saxe-Lauenburg was a German nobleman who ruled as the Duke of Saxe-Lauenburg from 1422 until his death in 1442. He was a member of the House of Ascania, a prominent dynasty in medieval Germany. His reign was marked by efforts to strengthen his duchy and maintain its independence amid the political complexities of the time. During his rule, Eric IV faced challenges from neighboring territories and worked to secure alliances. He was known for his diplomatic skills and attempts to foster peace in the region. His legacy includes contributions to the development of Saxe-Lauenburg as a significant political entity in northern Germany.