Eric IV, also known as Eric Ploughpenny, was a king of Denmark who reigned from 1250 to 1259. He was the son of Abel of Denmark and Mechtilde of Holstein. His reign was marked by conflicts with the nobility and struggles for power, which ultimately led to his downfall. Eric IV's rule ended when he was deposed by his half-brother, Christopher I of Denmark. After his deposition, Eric IV's life took a turn as he became a monk, living out his days in a monastery. His reign is often remembered for the challenges he faced in maintaining authority over a divided kingdom.