Rev Ian Adair Muirhead was born 16 August 1913 in Falkirk. The son of Rev John Muirhead, minister of Falkirk Irving, and Isabel Cumming, he was educated at Falkirk Carmuirs Primary School and High School between 1925-30. He attended the University of Glasgow between 1930-1937, gaining an MA in Mental Philosophy (1st class honours), and a BD in Ecclesiastical History (Distinction).
He was licensed by the Presbytery of Falkirk on 14 April 1937, and ordained as assistant in Glasgow, Springburn Hill, where he worked from 1937-1940. On 9 May 1940, he moved to Forfar St James. He had his war service with Church of Scotland Huts and Canteens.
He married Margaret Knox Napier, only daughter of Rev Thomas McReadie Napier and Jane Knox, on 12 July 1940. They had three sons, John Ninian Adair Napier, Robin James Napier and Andrew Thomas Napier.
He transferred from Forfar St James and was inducted at Motherwell Brandon on 15 September 1948, remaining minister there until 1964. He was Lecturer then Senior Lecturer in Ecclesiastical History at the University of Glasgow from 1964 to 1978. He retired from the University in 1978 and after a brief interval he became minister of the parishes of Blairdaff and Monymusk in 1979. He finally retired in 1982 and moved to Livingston. He contributed to the Expository Times and the Scottish Journal of Theology amongst others. He was elected President of the Scottish Church History Society in 1977 for three years.
He died suddenly on 21 May 1983, while attending the General Assembly of the Church of Scotland in Edinburgh.