Theologian, liturgical scholar and World Methodism's leading ecumenist. He taught at The Queen's College, Birmingham 1973-79, before moving to America, first to Union Seminary, New York and then to Duke Divinity School, North Carolina. His Doxology (1980) was a pioneering attempt to write a systematic theology from a primarily liturgical perspective. He served on the Faith and Order Committee of the World Council of Churches from 1977 to 1991 and was co-ordinator of the 'Baptism, Eucharist, Ministry' process that produced the 'Lima Report' of 1982. His involvement from the late 1970s in various international bilateral ecumenical dialogues is reflected in his Methodists in Dialog (1995). He had an enormous influence on the Methodist-Roman CatholicismRoman Catholic dialogue, on which he served for 28 years, 25 of them as Methodist co-chair. He hoped to set up a dialogue with the Orthodox, but was frustrated in his aim by internal Orthodox differences over this at the time. His theological output was prodigious, nearly two hundred articles being listed at the time of his festschrift in 2003.