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
Maurice Berkeley, 3rd Baron Berkeley was disinherited by his elder brother William Berkeley, 1st Marquess of Berkeley, 2nd Baron Berkeley (1426–1492), who died without surviving progeny. As he never therefore possessed Berkeley Castle, he had no claim to the ancient feudal barony of Berkeley, which was dependent on landholdings. It was assumed (according to a very unusual legal rationale) that the barony by writ created in 1412 was also held dependent on the tenure of Berkeley Castle (that is to say it was deemed a feudal barony or barony by tenure), and that it had thereby been forfeited by association, and thus Maurice never assumed