Born the son of Ronald Stroyan, a judge,[5] in Scotland, John was educated at Harrow School.
He attended the University of St Andrews[6] (whence he gained his Master of Theology {MTh} degree in 1976)[5] and trained for the ministry at Queen's College, Edgbaston.
[7] Stroyan was ordained deacon at Petertide (3 July) 1983 by Keith Arnold, Bishop of Warwick,[8] and ordained priest the Petertide following (1 July 1984) by John Gibbs, Bishop of Coventry, both times at Coventry Cathedral,[9] and served his title post as assistant curate of St Peter's, Hillfields[10] (in the "Coventry East" team ministry).
From 1987 until 1994 he was Vicar of St Matthew with St Chad, Smethwick[11] (in the Diocese of Birmingham) then Bloxham with Milcombe and South Newington (in the Cotswolds) for a further eleven years, the last three as Area Dean of Deddington.
His pastoral dedication and his priority of spiritual renewal led to his appointment in 2005 to the episcopate[12] when Anthony Priddis was translated to Hereford.