 His father was added to the group on 2 June.Following his father's death on 22 April 1459, Walter Devereux assumed his place as the Steward of York's lands in Radnor, and in the Duke's retinue.He was with the Duke of York at the Battle of Ludford Bridge on 12 October 1459, but surrendered and threw himself on the King's mercy when York fled to Ireland following the defeat.