Thomas de Berkeley, 1st Baron Berkeley Thomas de Berkeley, 1st Baron Berkeley Thomas de Berkeley, 1st Baron Berkeley (c.1251 – 23 July 1321), "The Wise", feudal baron of Berkeley, of Berkeley Castle in Gloucestershire, England, was a peer, soldier and diplomat. 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". Thomas de Berkeley was born around 1251 at Berkeley Castle in Gloucestershire, the son of Sir Maurice de Berkeley, feudal baron of Berkeley, by his wife Isabel
Thomas de Berkeley, 5th Baron Berkeley to that of his contemporary Sir Maurice Russell (d.1416) at Dyrham, who was the father-in-law of Gilbert Denys, one of Berkeley's feoffees. Having died without male progeny the succession to the vast Berkeley estates became disputed, and eventually resulted in the Battle of Nibley Green (1469/70), the last battle fought in England entirely between the private armies of feudal magnates, fought near Berkeley Castle on 20 March 1469/70 between the troops of Thomas Talbot, 2nd Viscount Lisle and William Berkeley, 2nd Baron Berkeley, later 1st Marquess of Berkeley. Lisle and William Berkeley had long been engaged in a dispute over