In 1887 he removed to Glasgow as professor of church history; he had also been appointed in 1886 to a chaplaincy to Queen Victoria.
In 1644 he retired to Oxford, and held a chaplaincy at New College until the city surrendered to the parliamentary forces in 1646.
After losing the Hull chaplaincy through a change of ministry in 1714, he devoted himself to writing.
In 1686 he accepted the invitation to the first court chaplaincy at Dresden.
He next obtained a chaplaincy in the navy, from which he appears to have been speedily dismissed for bad conduct with the reputation of worse.
In May 1521 he was appointed to a chaplaincy attached to the altar of La Gesine in the cathedral of Noyon, and received the tonsure.
He was ordained in 1795, and after holding a chaplaincy in India at Barrackpur (1797-1799) was appointed Calcutta chaplain and vice-principal of the college of Fort William.
He accordingly obtained a chaplaincy under the East India Company and left for India on the 5th of July 1805.
He held at the same time the chaplaincy of Lincoln's Inn, for which he had resigned Guy's (1846-1860), but when he offered to resign this the benchers refused.
Wished to appoint him canon of Windsor, but the prime minister, Lord Liverpool, objected; Sumner received instead a royal chaplaincy and librarianship, and other preferments quickly followed, till in 1826 he was consecrated bishop of Llandaff and in 1827 bishop of Winchester.