He was s of William GRAY MUIR. He m 1963 Alexandra Mary b 1941 d of Brig William Alexander STEVENSON, later MACKENZIE OF GAIRLOCH DSO OBE 1912-82 and Marjory Charlotte nee STIRLING, MACKENZIE OF GAIRLOCH 1920-88 d of Sir John STIRLING OF FAIRBAIRN KT MBE TD 1893-1975 and Marjory Kythe 1892-1971 d of Maj Sir Kenneth John MACKENZIE 7th Bt KT MBE 1893-1975 of Gairloch and Lady Marjorie Louisa MURRAY CBE 1862-1943 d of gd of 3rd Earl of MANSFIELD & (4th) MANSFIELD KT 1806-98, and had a son (William John b March 1966) and a dau (Elizabeth Kythe b 1963, m 1990 Archibald b 1961 s&h of Col Sir James STIRLING OF GARDEN KCVO CBE TD b 1930 and Fiona Janetta Sophia Wood PARKER scion of that gentry family f/o Fairlie, and had a son and two daus) as above.