Maurice de Berkeley 1243 and, on 14 December 1243, he had livery of his father's lands. He fought in the war in North Wales and in 1264 he joined the Barons against King Henry III. Berkeley died on 4 April 1281 and was buried in St Augustine's Abbey in Bristol. Maurice de Berkeley Sir Maurice de Berkeley "the Resolute" (1218 - 4 April 1281), 5th (feudal) Baron de Berkeley, was an English soldier and rebel, residing at Berkeley Castle in the English county of Gloucestershire. Maurice was born in 1218 to Thomas de Berkeley and Joan de Somery. He married Isabel FitzRoy, the
Nottingham Castle were acting as Regents during Edward's minority following their murder of his father Edward II at Berkeley Castle. William Montagu and his companions, were accompanied by William Eland, castellan and overseer of Mortimer's castle, who knew the location of a secret tunnel which would take them up to a locked door higher up in the castle to a normally locked door. In the dark of night on 19 October 1330, Montagu and his companions entered the tunnel, climbed up to the door, which had now been unlocked either by Edward III or a trusted servant, overpowered Mortimer, killing Mortimer's personal