Page "Danelaw" Paragraph 23

867 Following the loss of York, Osberht and Ælla formed an alliance against the Danes.

They launched a counter-attack, but the Danes killed both Osberht and Ælla and set up a puppet king on Northumbrian throne.

In response, King Æthelred of Wessex, along with his brother Alfred marched against the Danes, who were positioned behind fortifications in Nottingham, but were unable to draw them into battle.

In order to establish peace, King Burhred of Mercia ceded Nottingham to the Danes in exchange for leaving the rest of Mercia undisturbed.