Walsingham—the name was assumed between 1758 and 1761—throughout his political life was connected with the Cavendish family, to whom he was related by the marriage of his kinswoman Lady Charlotte Boyle to the 4th Duke of Devonshire. Soon after he came of age he was returned for Knaresborough, a pocket borough which Lady Charlotte had brought into the Devonshire family. He made his first reported speech on 15 Apr. 1760 against the Scottish militia bill. He was not returned for Knaresborough in 1761, possibly because he was away at sea; but a seat was soon found for him at Fowey. Newcastle wrote to Devonshire on 12 June:
Walsingham served on the expedition to Martinique in 1762, and was apparently absent from England when the peace preliminaries were debated. In all the divisions on general warrants he voted with the Opposition; belonged to Wildman’s Club; and was counted by Newcastle as a ‘sure friend’. He attended the meeting of Opposition leaders at Claremont on 30 June 1765, and with the Cavendishes supported the decision to take office without Pitt.
Walsingham’s name appears in 11 division lists 1768-74, each time in opposition; and he acted as a teller in the division of 13 Feb. 1771 on the Spanish convention. ‘Though warm in party’,
Walsingham commanded a ship in Admiral Keppel’s fleet which fought the indecisive battle with the French off Ushant in July 1778. Later in the year, when the Keppel-Palliser controversy was coming to a head, Sandwich wrote of him to the King:
Captain Walsingham has behaved well as an officer in a ship miserably manned. Busy, meddling, of a trifling disposition, not steady on either side, but leaning to Admiral Keppel in consequence of his politics.
In fact Walsingham was most anxious that the dispute should not become a party point or affect the morale of the navy. He wrote to Sandwich on 11 Nov. 1778:
Whenever it is mentioned amongst us it is talked of as a most unhappy affair which rose from nothing and may end unpleasantly; but there is no party in the case, indeed there is no grounds for it.
In the Commons on 10 Dec. he opposed Temple Luttrell’s motion for a court martial on Palliser.
An even more remarkable example of his independence and integrity was his defence of the Admiralty during the debate of 19 Apr. 1779 on Fox’s motion for the dismissal of Sandwich:
He said no man who ever sat at the Admiralty Board had exerted himself with more zeal or more effectually than the noble Lord who at present presides there.
And of himself: ‘He was an independent man, and was ready to put the smiles or frowns of either side of the House equally at defiance.’ Only on naval affairs did Walsingham depart from the Opposition line: he seems never to have changed his opinion on the American war; and Robinson classed him as an opponent both on the contractors bill, 12 Feb. 1779, and in his survey for the general election of 1780. But Walsingham had a close personal friendship with Sandwich, despite their difference in politics. Sandwich wrote to him the morning after the murder of Martha Ray, Sandwich’s mistress:
My Dear Walsingham,
For God’s sake come to me immediately, in this moment I have much want of the comfort of a real friend. Poor Miss Ray was inhumanly murdered last night as she was stepping into her coach at the playhouse door.
I am ever yours, Sandwich.
In June 1780 Walsingham sailed in the Thunderer with a squadron for the West Indies. In October the ship was lost in a hurricane off Jamaica. Walsingham had been returned again for Knaresborough at the general election, and for some months hopes were entertained that his ship might have survived. But in June 1781 his death was presumed, and a new writ was ordered.
