He was born in Penzance and educated at Truro School, Clare College and Wesley House, Cambridge. A WCC scholarship enabled him to undertake research on Luther at Lund University. Two years (1965-1967) at the University of Strasbourg and Munster led to a doctorate, published in 1970 as The Holy Spirit in the Theology of Martin Bucer. From 1995 on he was President of the Society for Reformation Studies and in 1997 he won the Max Geilinger Prize for The Theology of Huldrych Zwingli (OUP, 1986).
He was Assistant Tutor at Hartley Victoria College 1958-1961, Chaplain at Nottingham University 1961-1965, tutor in Church History at Hartley Victoria College 1971-1973, in historical and systematic theology at Wesley College, Bristol 1973-1980 and in church history at the Queen's College, Birmingham 1981-1986. From 1986 to 1999 he was Professor of Church History at Aberdeen University, where he was Dean of the Faculty of Divinity 1986-1988 and Provost of the Faculty 1988-1989.
He has served on a number of connexional committees: Local Preachers (1962-1965), European Relations (1967-1987),Faith and Order (1980- ) and Overseas Division (1982- ) and on the *Roman Catholic-Methodist Commission (1972-1980). He was President of the Conference in 1998. In retirement since 1999, he has remained in the active work and from 2003 to 2004 was Chairman and General Superintendent of the Methodist Church in The Gambia. From 2010 to 2012 he served as the first Presiding Bishop of The Gambia's Methodist Church.
He is a linguist who has travelled and preached in many European countries and has been closely involved in the Conference of European Churches and on World Methodist Church commissions. He wrote a booklet on Methodism in Europe (1993), published in both Britain and America. In retirement he has continued in the active work. He is a keen sportsman and hill-walker.