Hall, Hertfordshire, and at Melbourne House, Piccadilly (now the Albany), which was purchased from Lord Holland in 1770, and became an important whig centre. In 1790 he was painted by Reynolds, together with his brothers Peniston and Frederick [q. v.], in the picture ‘The Affectionate Brothers’ (see Haydon, Autobiography, ii. 343, and C. R. Leslie, Autobiographical Recollections, pp. 169, 170). The picture was engraved by Bartolozzi and S. M. Reynolds. He went to Eton in 1790, where he reached the sixth form, and in July 1796 was entered a fellow-commoner of Trinity College, Cambridge, going into residence in the following October. He was also entered at Lincoln's Inn on 21 July 1797. In Michaelmas term 1798 he won the Trinity declamation prize by an oration on ‘The Progressive Improvements of Mankind,’ which was praised by Fox in the House of Commons (Speeches of C. J. Fox, vi. 472). He proceeded to his degree on 1 July 1799, having spent most of his time at Cambridge in private study. He wrote an ‘Epistle to the Editor of the Anti-Jacobin,’ published in the ‘Morning Chronicle’ of 17 Jan. 1798, sharply answered by Canning, and an epilogue to Sheridan's ‘Pizarro,’ performed at Drury Lane on 24 May 1799. In the winter of 1799 he went with his brother Frederick to Glasgow as a resident pupil of Professor Millar. His letters to his mother (Lord Melbourne's Papers, pp. 5–30) show that he worked hard and took a keen interest in literature. At the same time he was rather precocious and an extreme whig in his opposition to the French war. He wrote many verses at this time, contributed to the ‘Bugle,’ a weekly paper, written by the guests at Inverary Castle, under the editorship of ‘Monk’ Lewis (Memoirs of M. G. Lewis, i. 199), and wrote an epilogue on ‘The Advantages of Peace’ for Miss Berry's ‘Fashionable Friends,’ acted May 1802 (see Miss Berry's Journal, ii. 196). Lamb was called to the bar in Michaelmas term 1804, and went the northern circuit. At the Lancashire sessions he was much pleased at receiving a complimentary brief through Scarlett (Lord Abinger). On the death of his elder brother Peniston, on 24 Jan. 1805, he gave up the bar for politics. On 3 June he married Lady Caroline Ponsonby, only daughter of the third Earl of Bessborough, by whom he had been previously rejected [see Lamb, Lady Caroline].
On 31 Jan. 1806 Lamb was returned for Leominster in the whig interest. Soon afterwards he inscribed some passable lines on the pedestal of the bust of Charles James Fox. On 19 Dec. 1806 he made his maiden speech as mover of the address. In the following March he began to keep a diary, which he continued during the two following years. It records the downfall of the ‘Talents’ administration, in defence of whose conduct Lamb on 9 April seconded a resolution moved by Mr. Brand. At the general election he was returned for Portarlington (23 May 1807). He had now lost his boyish zeal for Napoleon, and took a deep interest in the success of the Peninsular war. Though he rarely spoke, he was selected on 31 Dec. 1810 to move an amendment to the Regency Bill. His speech was commended by Canning, whom, in spite of early prejudices, he had already begun to follow. In consequence of this, when Lamb lost his seat in 1812 for his support of catholic emancipation, Brougham wrote to Grey that his defeat at the polls was not to be regretted (Brougham's Life and Times, ii. 25, 64).
Lamb was out of parliament for four years. In 1813 his wife's temper led him to attempt a separation, which was not, however, carried out till 1825. From certain entries in his commonplace-book, quoted in ‘Lord Melbourne's Papers’ (pp. 71, 72), it may be gathered that the husband and wife were from the first an ill-assorted couple. Lamb was certainly a kind, if too indulgent, husband. He sought distraction from domestic troubles in sport, society, and literature. He was an excellent shot, and something of a field naturalist. But literature was his chief solace, and his commonplace-book contains a record of his studies, which embraced the greater part of the classics and many English historians. No record of his theological reading has been preserved. His reflections on society, suggested by his studies, are couched in a very cynical vein. In spite of his learning, however, he shrank from authorship, though he was an occasional contributor to Jerdan's ‘Literary Gazette’ (Jerdan, Autobiography, ii. 284–6, where a poem of Lamb's is identified), and wrote a sketch of the early part of Sheridan's political life, which in 1819 he handed over to Moore (Moore, Diary, ii. 306, 308). Lamb subsequently regretted the step (Mrs. Norton, in Macmillan's Magazine, vol. iii.)
Lamb was returned to the House of Commons on 16 April 1816 as member for Northampton, and on 29 Nov. 1819 was elected one of the members for Hertfordshire, but retired from a contest for Hertford borough in 1825, because the electors preferred the uncompromising radicalism of Thomas Duncombe [q. v.] He had made little mark as yet, though Castlereagh and the regent and others foresaw his future eminence. He was a lukewarm whig, and though in 1819 he supported Lord Althorp's motion for an inquiry into the
