Cranfield became next Earl of Middlesex, after his brother, in 1651. Around 1655, he married Rachel, daughter of the Earl of Westmorland and widow of Henry Bourchier, 5th Earl of Bath. In May 1660, he was one of the six people selected by the Convention Parliament to ask Charles II of England to come back. He became a Gentleman of the Bedchamber to Charles II in 1673. He died the next year without children; his titles went to no one, and his property went to the son of his sister, Charles Sackville, 6th Earl of Dorset.