Henry John Temple (1784-1865) Third Viscount Palmerston (Ireland) from 1802. Secretary at War, 1809-28. (Later Foreign Secretary, 1830-34, 1835-41, 1846-51, Home Secretary, 1852-55, and Prime Minister, 1855-58, 1859-65). Educated at Harrow, Edinburgh and St John’s College, Cambridge. He was the son of a Portland Whig who was an MP for 40 years, holding minor office under Rockingham, Grafton and North. Palmerston turned down the Exchequer in 1809 and then as Secretary at War spent the next eighteen years outside the Cabinet, being admitted only under Canning. He was a supporter of Catholic Emancipation but not close to Canning personally, a moderate Commons speaker who stuck mostly to departmental matters and lacked the fluency in general debate which would have made his promotion inevitable. While diligent in administration, he also enjoyed an active ‘social life’, producing several illegitimate children.
Palmerston broke with Liverpool over the Cambridge University election of 1826, when he and the other sitting member William John Bankes were opposed by two ministers, Copley and Goulburn, who opposed Catholic Emancipation (the position favoured by the largely clerical Cambridge University graduate electorate). He thus welcomed Canning’s advent to power in 1827 and resigned with Huskisson from Wellington’s government, moving thereafter towards the Whigs. Mrs Arbuthnot liked Palmerston before they became political opponents; in 1824 she wrote, ‘I like Lord Palmerston very much; he is very gentlemanlike and sensible and seems very amiable’1.
 Bamford and Wellington, The Journal of Mrs. Arbuthnot, 1820-32, Vol. 1, p. 419.
Information on how Palmerston stacks against other Prime Ministers can be found in his Contenders entry