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.