King Henry III of England created the Earldom of Lancasterfrom which the royal house of Henry IV was namedfor his second son, Edmund Crouchback, in 1267. Edmund had already been created Earl of Leicester in 1265 and following the Second Barons' War and the death and attainder of the king's rebellious brother-in-law Simon de Montfort, 6th Earl of Leicester in 1265, the latter's lands, including most notably Kenilworth Castle in Warwickshire, had been awarded to him.