Cavendish returned from the continent in 1645, submitted to the parliament, was pardoned for his former delinquency in 1646, was fined £5,000, and lived in retirement with his mother at Latimer, Buckinghamshire.
Cavendish, a virtuoso, was close to John Evelyn, and was one of the original fellows of the Royal Society (20 May 1663), He was a commissioner of trade 5 March 1668 - 1669, but lived mainly in the country.