[1][2] In 1825, Cardwell was chosen Camden Professor of Ancient History and held the chair for 35 years, the longest of any occupant to date.
In 1831, he succeeded Archbishop Whately as principal of St Alban Hall (later merged with Merton College).
He planned an extensive work on the entire synodical history of the church in England, which was to be based on David Wilkins's Concilia Magnae Britanniae et Hiberniae.
On 1842 appeared Synodalia, a Collection of Articles of Religion, Canons, and Proceedings of Convocation from 1547 to 1717, completing the series for that period.
Closely connected with these works is the Reformatio Legum Ecclesiasticarum (1850), which treats of the efforts for reform during the reigns of Henry VIII, Edward VI, and Elizabeth I.