son of Henry Temple, second viscount [q. v.], by his second wife, Mary, daughter of Benjamin Thomas Mee of Bath. He was born at his father's English estate, Broadlands, Hampshire, on 20 Oct. 1784. Much of his childhood was spent abroad, chiefly in Italy, and at home his education was begun by an Italian refugee named Ravizzotti; but in 1795 he entered Harrow, where he rose to be a monitor, and thrice ‘declaimed’ in Latin and English at speeches in 1800. Althorp and Aberdeen were among his schoolfellows. In 1800 he was sent to Edinburgh to board with Dugald Stewart [q. v.] and attend his lectures. Here, says Lord Palmerston (in a fragment of autobiography written in 1830), ‘I laid the foundation for whatever useful knowledge and habits of mind I possess.’ Stewart gave him a very high character in every respect; and to moral qualities the boy added the advantage of a strikingly handsome face and figure, which afterwards procured him the nickname of ‘Cupid’ among his intimates. From Edinburgh he proceeded to Cambridge, where he was admitted to St. John's College on 4 April 1803 (Register of the College). Dr. Outram, afterwards a canon of Lichfield, was his private tutor, and commended his pupil's ‘regularity of conduct.’ At the college examinations Henry Temple was always in the first class, and he seems to have regarded the Cambridge studies as somewhat elementary after his Edinburgh training. He joined the Johnian corps of volunteers, and thus early showed his interest, never abated, in the national defences. He did not matriculate in the university till 27 Jan. 1806, and on the same day he proceeded master of arts without examination, jure natalium, as was then the privilege of noblemen (Reg. Univ. Cambr.) By this time he had succeeded to the Irish peerage on his father's death on 16 April 1802.
In 1806, while still only an ‘inceptor,’ he stood in the tory interest for the seat of burgess for the university, vacant by the death of Pitt, and, though Lord Henry Petty won the contest, Palmerston was only seventeen votes below Althorp, the second candidate. In the same year, at the general election, he was returned for Horsham at a cost of 1,500l.; but there was a double return, and he was unseated on petition 20 Jan. 1807. After again contesting Cambridge University in May 1807, and failing by only four votes, he soon afterwards found a seat at Newtown, Isle of Wight, a pocket borough of Sir Leonard Holmes, who exacted the curious stipulation that the candidate, even at elections, should ‘never set foot in the place.’ By the influence of his guardian, Lord Malmesbury, he had already (3 April 1807) been appointed a lord of the admiralty in the Portland administration, and his first speech (3 Feb. 1808) related to a naval measure. He rose to defend the government against an attack directed upon them for not laying before the house full papers on the recent expedition to Denmark. The speech was a vindication of the necessity of secrecy in diplomatic correspondence. Although a rare and only on great occasions an eloquent speaker, he was a close observer of current political movements, and a journal which he kept from 1806 to 1808 shows that he early devoted particular attention to foreign affairs. In October 1809 the new prime minister, Spencer Perceval, offered Palmerston conditionally the choice of the post of chancellor of the exchequer, of a junior lordship of the treasury with an understood succession to the exchequer, or of secretary at war with a seat in the cabinet. The young man consulted Lord Malmesbury and other friends, but he had already made up his mind. He clearly realised the dangers of premature promotion, and accordingly declined the higher office, accepting the post of secretary at war, but without a seat in the cabinet. He was sworn of the privy council on 1 Nov. 1809.
Palmerston entered upon his duties at the war office on 27 Oct. 1809, and held his post for nearly twenty years (till 1828) under the five administrations respectively of Perceval, Lord Liverpool, Canning, Lord Goderich, and (for a few months) the Duke of Wellington. Apparently he was content with his work, for he successively declined Lord Liverpool's offers of the post of chief secretary for Ireland, governor-general of India, and the post office with an English peerage. Like not a few English statesmen of high family and social tastes, he had at that time little ambition, and performed his official labours more as a duty to his country than as a step to power. He was, in fact, a man of fashion, a sportsman, a bit of a dandy, a light of Almack's, and all that this implied; also something of a wit, writing parodies for the ‘New Whig Guide.’ His steady attachment to his post is the more remarkable, since the duties of the secretary at war were mainly concerned with dreary financial calculations, while the secretary for war controlled the military policy. Palmerston held that it was his business to stand between the spending authorities—i.e. the secretary for war and the commander-in-chief—and the public, and to control and economise military expenditure in the best