John Berkeley (1352–1428) 1394, for Wiltshire in 1402 and Hampshire in 1406. He married 3 times, but had issue only by his third wife, Elizabeth Betteshorne. John Berkeley (1352–1428) Sir John Berkeley (1352–1428), of Beverston Castle, Gloucestershire was an English politician. He was the son of Thomas de Berkeley, 3rd Baron Berkeley of Berkeley Castle and Katherine Clivedon. He was knighted before 1383. He was appointed High Sheriff of Somerset and Dorset for 1390–91 and 1394–95, High Sheriff of Gloucestershire for 1392–93, 1397–98 and 1414–15, High Sheriff of Hampshire for 1402–03 and 1406–07, and High Sheriff of Wiltshire for 1410–11. He was a
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