He m 1st 1963 (div 1972) as her 1st h (her 2nd was 6th Baron Hothfield b 1935) Lucinda Marjorie (Lady Hothfield) b 1946 d of Capt Timothy John GURNEY 1921-2001 (s of Christopher William GURNEY c1898-1939 (s of Cyril GURNEY 1868-1926 (s of Rev Alfred GURNEY 1843-98 and Alice Blanche GIBBS 1843-71 gd of Antony GIBBS 1756-1815 (gf of 1st Baron ALDENHAM 1819-1907 and gt gf of 1st Baron WRAXALL 1873-1931) and gd of Sir Thomas CRAWLEY-BOEVEY 3rd Bt 1769-1847))) and Jean Doris GRENFELL d 1958 2xgt gd of Pascoe GRENFELL 1761-1838 (gf of 1st Baron GRENFELL 1841-1925) and 3xgt gd of 1st Viscount DONERAILE d 1787) and Bridget DE BATHE 1922-2011 (gd of Gen Sir Henry Perceval DE BATHE 4th Bt 1823-1907), and had a son (Simon Morison b 1968).
He m 2nd 1972 (div 197_) Jane b 1943 d of Maj Thomas Edward Dealtry KIDD 1910-79 and as her 3rd h (her 1st was 11th Duke of Argyll & her 2nd h was a son of 9th Earl of Sandwich) Hon Janet Gladys AITKEN 1908-88 d of 1st Baron BEAVERBROOK 1879-1964.
He m 3rd 1980 (div 1992) as her 2nd h (her 1st was John B A Alexander) Jacquelyn W BRAY, and had a further son (Harry Michael b 1983, see below).
He m 4th 1994 reg Q4 Leics, as her 2nd h (her 1st was John M Davis) Sally D d of John W ANDERTON OBE of Worthenbury, Clwyd, and had two daus (Poppy Elizabeth b 1995 and Rose Victoria b 1998).
See link for details of his son Harry Michael’s m & issue and his wife's family connections: https://groups.google.com/g/peerage-news/c/DptsW33--oY/m/RBB7cOheAQAJ
From the Telegraph of 11 March 2023: VERE NICOLL Graham Morison. A Memorial Service will be held at Chelsea Old Church, 64 Cheyne Walk, London… at 2.30 p.m. on Friday 21st April...