Allen was educated at Dulwich College[3] and University College, Oxford, and after training at Ripon Hall was ordained in 1927.[4] Following a brief curacy at St Saviour's, Liverpool, he was Chaplain of his old theological college, a Fellow of Lincoln College, Oxford, Lecturer at Union Theological College, Canton, the Deputy Provost of St Philip's Cathedral, Birmingham and then Archdeacon of Birmingham, 1944–47.