Thomas de Berkeley, 5th Baron Berkeley Thomas de Berkeley, 5th Baron Berkeley Thomas de Berkeley, 5th Baron Berkeley (5 January 1352/53 – 13 July 1417), "The Magnificent", of Berkeley Castle and of Wotton-under-Edge in Gloucestershire, was an English peer and an admiral. His epithet, and that of each previous and subsequent head of his family, was coined by John Smyth of Nibley (d.1641), steward of the Berkeley estates, the biographer of the family and author of "Lives of the Berkeleys". He was born at Berkeley Castle in Gloucestershire, the son and heir of Maurice de Berkeley, 4th Baron Berkeley by his wife Elizabeth le Despencer. In
Baron Berkeley was created Viscount Berkeley in 1481, Earl of Nottingham in 1483, and Marquess of Berkeley in 1488. He had no surviving male issue, so the Marquessate and his other non-inherited titles became extinct on his death in 1491, whilst the barony passed "de jure" to his younger brother Maurice. However William had disinherited Maurice because he considered him to have brought shame on the noble House of Berkeley by marrying beneath his status to Isabel, daughter of Philip Mead of Wraxhall, an Alderman and Mayor of Bristol. Instead he bequeathed the castle, lands and lordships comprising the Barony of Berkeley