Edgar (or Eadgar), c. 944 – 8 July 975, also known as Edgar the Peacemaker and the Peaceable, was King of the English from 959 until his death in 975. He became king of all England on his brother Eadwig's death. He was the younger son of King Edmund I and his first wife, Ælfgifu. A detailed account of Edgar's reign is not possible, because only a few events were recorded by chroniclers and monastic writers, who were more interested in recording the activities of the leaders of the church.
Edgar mainly followed the political policies of his predecessors, but there were major changes in the religious sphere. The English Benedictine Reform, which he strongly supported, became a dominant religious and social force. It is seen by historians as a major achievement, and it was accompanied by a literary and artistic flowering, mainly associated with Æthelwold, Bishop of Winchester. Monasteries aggressively acquired estates from lay landowners with Edgar's assistance, leading to disorder when he died and former owners sought to recover their lost property, sometimes by force. Edgar's major administrative reform was the introduction of a standardised coinage in the early 970s to replace the previous decentralised system. He also issued legislative codes which mainly concentrated on improving procedures for enforcement of the law.