He was born at Meanwood in Yorkshire, and educated at Leeds Grammar School. His parents, Marmaduke and Jane, were from families with Irish ancestry. He was awarded a scholarship to study Classics at Pembroke College, Oxford and graduated with first honours in 1904, before obtaining work as an assistant in the British Museum in 1906. It was during his early years at the museum that he began learning Irish, with the museum authorities supporting his study of the language in Ireland. He married Ida Mary Streeter in 1911.