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 cognomen "Ironside" was given to him "because of his valour" in resisting the Danish invasion led by Cnut.
Edmund in the early 14th-century Genealogical Roll of the Kings of England
The ruins of Glastonbury Abbey in Somerset, where Edmund was buried
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".
Æthelred II in an early thirteenth-century copy of the Abingdon Chronicle
Gold mancus of Æthelred wearing armour, 1003–1006
Silver penny of Æthelred II
A charter of Æthelred's in 1003 to a follower, also called Æthelred. British Library, London