Edmund Ironside succeeds his father Æthelred the Unready as King of England.

Edmund Ironside was King of the English from 23 April to 30 November 1016. He was the son of King Æthelred the Unready and his first wife, Ælfgifu of York. Edmund's reign was marred by a war he had inherited from his father; his epithet "Ironside" was given to him "because of his valour" in resisting the Danish invasion led by Cnut.

Æthelred II, known as Æthelred the Unready, was King of the English from 978 to 1013 and again from 1014 until his death in 1016. His epithet comes from the Old English word unræd meaning "poorly advised"; it is a pun on his name, which means "well advised".

April 23 is the 113th day of the year in the Gregorian calendar; 252 days remain until the end of the year.