After that, Greenslade studied to become a
priest and served as
curate at
Beeston in 1929–30. He was then elected a
fellow and
chaplain of
St John's College, Oxford, in 1930, where he was also the
librarian. There, he began a research project on
William Tyndale, which resulted in
The Work of William Tindale (1938), and also became an expert in the North African
Fathers of the Church. He left St John's College in 1943 to take up the
Lightfoot Professorship of Divinity at
Durham University, which came with a
canonry at
Durham Cathedral. He authored
The Church and the Social Order (1948) and gave the
Edward Cadbury Lecture at the
University of Birmingham in 1949–50. In 1950, he succeeded
Michael Ramsey as
Van Mildert Professor of Divinity at Durham. During his time in that chair, he authored
Schism in the Early Church (1953; 2nd ed. 1964),
Church and State from Constantine to Theodosius (1954, which he had given as the
Frederick Denison Maurice Lecture at
King's College London in 1953) and
Early Latin Theology: Selections from Tertullian, Cyprian, Ambrose and Jerome (1956). In 1958, he moved to the
University of Cambridge to take up the
Ely Professorship of Divinity; he was a canon of
Ely Cathedral and a fellow of
Selwyn College. But the next year, he was offered the
Regius Professorship of Ecclesiastical History at the
University of Oxford and accepted it; it was attached to a canonry at
Christ Church, Oxford. In 1960, he was elected a
fellow of the British Academy. He then authored
The English Reformers and the Fathers of the Church (1960), (as editor)
The Cambridge History of the Bible: The West from the Reformation to the Present Day (1963), and
Shepherding the Flock (1967), and, from 1969, he began researching
Erasmus's use of the Church Fathers's theologies. He retired from his academic positions in 1972. He died on 8 December 1977. == References ==