When his father King Christopher I died in 1259, Eric was too young to rule in his own right. The Danish court appointed his mother, Queen Margaret, to rule as
regent. She was the daughter of Duke
Sambor II of Pomerania and Matilda of Mecklenburg, and was an intelligent woman. Immediately, she had to fight to keep her son on the throne from two powerful enemies; Archbishop
Jacob Erlandsen (ca. 1220–1274) and
Erik Abelsøn who was Duke of Schleswig from 1260 until his death in 1272. Archbishop Jacob had excommunicated the bishop who had anointed young Eric as king. Duke Eric was a nephew of King Christopher and had been in frequent conflict with the king. Believing the Wendish incursion showed the queen was weak, Duke Eric rebelled. The queen was forced to raise another army and march to Jutland to put the Duke in his place. She defeated the duke, and while he negotiated a truce with her, he gathered allies in northern Germany to help him attack. The combined forces defeated Queen Margaret in 1261 at the
Battle of Lohede south of
Danevirke in Schleswig-Holstein. She and her son were captured and were forced to cede royal properties in southern Jutland to secure their release. In 1260, Queen Margaret had released Archbishop Jacob from prison thinking he would be grateful, but he subsequently issued an
interdict over all of Denmark trying to force her and Eric off the throne. In 1263, acting as regent of Denmark, the queen wrote to
Pope Urban IV asking him to intervene with Archbishop Jacob. After several years of quibbling, the pope agreed to several items that the queen wanted. He issued a
dispensation to alter the terms of the Danish succession that would permit women to inherit the Danish throne. This would make it possible for one of King Eric's sisters to become queen in the event of his death, because he had no children. Although Pope Urban IV gave his consent, it never became an issue. King Eric's son
Eric Menved eventually succeeded to the Danish throne. ==Reign==