Having been awarded a scholarship, he studied literae humaniores (classics) at Hertford College, Oxford.
[1] On 15 June 1917, he relinquished his British Army commission on account of ill health, and was granted the honorary rank of captain.
Campion was appointed a Knight Commander of the Order of the Bath in the 1938 New Year Honours (KCB).
[11][12] He was appointed to be a Knight Grand Cross (GCB) in the 1948 Birthday Honours[13] and retired that year as Under Clerk of the Parliaments, when he was replaced by Frederic Metcalfe CB.
[14] In the 1950 Birthday Honours, his barony for "public services" was announced[15] and he was raised to the peerage as Baron Campion, of Bowes in the County of Surrey.