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
Margaret Mortimer, Baroness Berkeley Margaret Mortimer, Baroness Berkeley Margaret Mortimer, Baroness Berkeley (2 May 1304 – 5 May 1337) was the wife of Thomas de Berkeley, 3rd Baron Berkeley. She was the eldest daughter of Roger Mortimer, 1st Earl of March, the "de facto" ruler of England from 1327 to 1330, and his wife Joan de Geneville, Baroness Geneville. Margaret Mortimer was the eldest of the twelve children of Roger Mortimer, 1st Earl of March and Joan de Geneville, Baroness Geneville. Her paternal grandparents were Edmund Mortimer, 2nd Baron Mortimer and Margaret de Fiennes. Her maternal grandparents were Piers de Geneville, of Trim Castle