Born in Dundrum, County Tipperary and educated at Clongowes Wood and UCD, he continued his studies at Grenoble, Munich and Vienna where he was awarded the PhD for his dissertation on 10th and 11th century Anglo-Saxon manuscript illumination. He obtained a position as an Assistant Keeper at the National Gallery, London in 1930 and in 1935 was appointed Director of the National Gallery in Dublin, where he remained for fifteen years, lecturing and writing on art matters and acting as examiner in the history of European painting at both Trinity College and University College Dublin. He moved back to London in 1950.