Edmund Ironside (c. 990 – 30 November 1016; Old English: Ēadmund, Latin: Edmundus; sometimes also known as Edmund II) 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 cognomen "Ironside" was given to him "because of his valour" in resisting the Danish invasion led by Cnut the Great.