 In thanks for this service Edward gave him the manor of Elham in Kent, but in 1262 the grant was deemed to be in violation of the conditions of Henry giving the manor to Edward in the first place, and the manor was returned, with the High Sheriff of Kent being ordered to take £1,820 from Leybourne's lands; Leybourne frustrated him by simply removing all the goods from his lands in Kent, Essex and Sussex.In 1263 he along with other Marcher Lords arrested Peter of Aigueblanche, Bishop of Hereford, and seized Hereford, Gloucester, and Bristol, returning south to assault Windsor Castle.They were joined by Simon de Montfort, beginning the Second Barons' War.