 He was elected Bishop of Oxford in April 1671 and Bishop of Durham on 18 August 1674.He owed his rapid promotions to the Duke of York (later James VII & II), whose favour he had gained by secretly encouraging the duke's interest in the Roman Catholic Church.Crew baptised the Duke's daughter Princess Catherine in 1675 and was made a Privy Counsellor on 26 April 1676 He was present at the crucial Privy Council meeting in October 1678 where Titus Oates first revealed his great fabrication, the Popish Plot.