William de Berkeley, 1st Marquess of Berkeley William de Berkeley, 1st Marquess of Berkeley William de Berkeley, 1st Marquess of Berkeley (1426 – 14 February 1492) was an English peer, given the epithet "The Waste-All" by the family biographer and steward John Smyth of Nibley. He was buried at "St. Augustine's Friars, London" according to one source, but most likely in the Berkeley family foundation of St Augustine's Abbey, Bristol. William of Berkley was born to James Berkeley, 1st Baron Berkeley, and Lady Isabel Mowbray at Berkeley Castle in Berkeley, Gloucestershire, in 1426. His first marriage was in 1466 to Elizabeth West, daughter of Reginald West, 6th
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