Erik IV of Denmark, also known as Erik Ploughpenny, was a king who ruled from 1241 to 1250. He was the son of Valdemar II and Dagmar of Denmark. Erik's reign was marked by efforts to strengthen the monarchy and improve the kingdom's economy, particularly through agricultural reforms. During his rule, Erik IV faced challenges from the nobility and internal conflicts. He is known for his attempts to centralize power and reduce the influence of local lords. His reign ended when he was deposed, leading to a period of instability in Denmark.