He matriculated at the University of Oxford in 1868 as an unattached student, the following year joining Christ Church, where he took a first-class degree in law and modern history in 1872.

He became law-lecturer and tutor of Christ Church, fellow of Oriel College, delegate of the Clarendon Press, and in 1894 he was made Regius Professor of Modern History in succession to James Anthony Froude.

[6] Powell died on 8 May 1904 at Staverton Grange, Banbury Road, Oxford, and was buried in Wolvercote.

[7] Powell took an interest in French poetry, and Paul Verlaine, Stéphane Mallarmé, and Emile Verhaeren all lectured at Oxford under his auspices.

He had been attracted in his school days to the study of Scandinavian history and literature, and he was closely allied with Professor Guðbrandur Vigfússon (d. 1889), whom he assisted in his Icelandic Prose Reader (1897), Corpus Poeticum Boreale (1887), and Origines Islandicae (1905), and in the editing of the Grimm Centenary papers (1886).