Cadogan was returned for Cambridge in 1749 on the interest of Lord Montfort, supported by the Pelhams; in 1754 he made room for his brother-in-law, Thomas Bromley, and unsuccessfully contested Great Marlow; but he was again returned for Cambridge on Bromley’s succeeding to the peerage; and till 1774 his elections at Cambridge were uncontested. The appointment in the Duke of York’s ‘family’ in time created a new connexion, and as its senior member Cadogan naturally had to follow the Duke. In Bute’s list of December 1761, ‘Newcastle, Government’ was first placed against Cadogan; but next ‘Newcastle’ was crossed out. He appears in Fox’s list of Members in favour of the peace preliminaries; and writing to Bute, 30 Nov. 1762, Fox mentioned him among possible seconders of the Government motion.
In February 1766 Cadogan took a hand in trying to bring about a meeting and reconciliation between Grenville, Bedford, and Bute with a view to defeating the Rockinghams and the repeal of the Stamp Act
I have said he was attached to Grenville; it was because he thought Grenville likely to come into power again; but when deserted by the Bedfords, Cadogan paid his court to Lord Gower; and when Lord North became minister, became so servile to him, that being out shooting in Norfolk during the Newmarket season, it was a joke with the persons who returned thence to examine the game going to London, and at every inn was a parcel directed by Cadogan to Lord North.
By the beginning of 1768 Cadogan was back in the Government camp, towards which he had always gravitated; but more important than the failure of the negotiations for a united Opposition in July 1767, and the Bedfords joining Administration, was the death of the Duke of York in September 1767, which set Cadogan free to follow his own inclinations—and a careful study of the various collections of Grenville and Bedford mss. shows that at no time was he really close to either. Henceforth he is never found voting against the Government.
In 1770, on Granby’s death, Montfort thought of putting up Cadogan’s eldest son, Captain Cadogan, for the county;
Cadogan died 3 Apr. 1807.
