The financial ruin of Cockburn’s father was offset by the professional success of himself and his brothers, two of whom were in the army, one in the Church and one a diplomat. He had an eventful naval career, on the strength of which he sought a baronetcy in 1810.
Admiral Cockburn is brother to my brother-in-law William Cockburn, and is a very fine fellow. He is thought to be a severe disciplinarian, differs with Sir S. Romilly upon the effects of flogging, and with Sir John [Borlase] Warren upon the best mode of carrying on the warfare against America.
Add. 40287, f. 158.
In 1815 Cockburn escorted Buonaparte to St. Helena and treated him roughly.
Cockburn, on his appointment to the Admiralty board, was their candidate at Portsmouth in 1818, though Southampton had been considered for him. He ousted John Markham, one of the opposition Members, without a contest. In 1820 Adm. Markham defeated him, but he was found another seat. He first spoke on Admiralty business, 4 Feb. 1819. On 18 Mar. he denied that he had applied patronage at Portsmouth for electioneering purposes and opposed Ridley’s motion for the reduction of the junior lords of Admiralty. On 2 Apr. he defended General Gourgaud, arrested as an alien, having known him on St. Helena. He was in the minority on the Marriage Act amendment bill, 26 Apr. He opposed an aggrieved sailor’s petition, 11 May. He defended the navy estimates, 2 June. He was in the government majorities of 29 Mar., 18 May and 10 June. He opposed, as impracticable, Joseph Hume’s motion for information on the comparative costs of shipbuilding and outfitting since 1791, 8 Dec. 1819. He was described in 1824 as ‘an ungovernable man and his head turned by the dominion he holds at the Admiralty’.