He was born at Yateley (35 m. w.s.w. of London), Hampshire, July 15, 1814 son of Rev. R. C. Caswall, sometime Vicar of Yately, Hampshire. He died at the Oratory, Edgbaston, near Birmingham, January 2, 1878 and was buried at Rednal, near Bromsgrove.
Caswall studied at Brasenose College, Oxford (B.A., 1836; M.A., 1838). He graduated in 1836 with honors. He was curate of Stratford-sub-Castle, near Salisbury, 1840–47. In 1850, his wife having died the previous year, he joined the Oratory of St. Philip Neri under Newman, to whose influence his conversion to Roman Catholicism was due.
He wrote original poems that have mainly survived only in Catholic hymnals due to a clear adherence to Catholic doctrine. Caswell is best known for his translations from the Roman breviary and other Latin sources, which are marked by faithfulness to the original and purity of rhythm. They were published in Lyra Catholica, containing all the breviary and missal hymns (London, 1849); The Masque of Mary (1858); and A May Pageant (1865). Hymns and Prose (1873)are the three books combined with many of the hymns rewritten or revised.
- Julian, John (June, 1907). A Dictionary of Hymnology. London: John Murray. pp. 214–215.
- Bailey, Albert Edward (1950). The Gospel in Hymns. New York: Charles Scribner's sons. pp. 198–199.