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
Berkeley family docent and genealogist at the Berkeley Castle listed the Barclay clan as also descending from the de Berkeley clan through the matriarchal line Alice De Berkeley -- the woman who married Robert Fitzharding and restored the family's name. Additionally, historians on Scottish clans and surnames point out that the Barclay clan spelling moves into the Berkeley (pronounced Bar-Clay) spelling. This descends from Sir Maurice Berkeley (by 1514–81), a politician who rose rapidly in the Tudor court. He came from the Berkeleys of Stoke Gifford, a cadet branch of the main Berkeley family, as a descendant of Sir Maurice de Berkeley