He was the only child of Sir Cuthbert Barwick CLEGG TD 1904-86 and Helen Margaret 1906-87 d of Arthur John JEFFERSON 1857-1915 by his c1886 m reg Q1 Durham to Cecilia JAMES 1863-1946. He m 1963 (Katherine) Veronica b 1943 d of Archibald Andrew Henry DOUGLAS 1902-97 (2xgt gs of Sir William DOUGLAS 4th Bt c1731-1783 of Kelhead who was f of 6th & 7th Marquesses of QUEENSBERRY) and his former wife Marjorie Gordon BROWN d 1992, and had two sons and a dau.