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
Baron Berkeley that the barony by writ was deemed, extraordinarily, to be in effect a feudal barony (or barony by tenure), dependent on the tenure of Berkeley Castle. Thus when William Berkeley, 1st Marquess of Berkeley, 2nd Baron Berkeley (1426–1492), "William the Waste-All", alienated Berkeley Castle to the king, he effectively disinherited his younger brother from the barony by writ. The heir apparent is his son the Hon. Thomas FitzHardinge Gueterbock (b. 1969) The Earldom of Berkeley, together with the Viscountcy Dursley, was separated from the barony in 1882, but the accession was not fully established. In 1942 both titles became extinct