De Grey, Thomas Philip (1781–1859), 2nd Earl de Grey , politician and lord lieutenant of Ireland, was born 8 December 1781 at Whitehall, London, elder son of Thomas Robinson, 2nd Baron Grantham, and Mary Jemima, second daughter of Philip Yorke, 2nd earl of Hardwicke (his mother was therefore first cousin of the 3rd earl of Hardwicke (qv), lord lieutenant of Ireland 1801–5). In 1786 he succeeded as 3rd Baron Grantham; in 1803 he assumed the surname of Weddell in lieu of his patronymic; and in 1833 – having inherited the title of Earl de Grey – assumed the surname of De Grey in place of Weddell. He was educated at St John's College, Cambridge (MA 1801), became colonel of the Yorkshire hussar regiment of yeomanry (1831), was appointed yeomanry ADC to William IV, and held a similar post in 1837 under Queen Victoria.
Although at first a moderate tory – he supported catholic emancipation, voted with the whigs on the Queen Caroline affair, and made no dramatic party mark as first lord of the admiralty in the brief administration (1834–5) of Sir Robert Peel (qv) – this quickly changed on his becoming lord lieutenant of Ireland (again under Peel) from September 1841 to July 1844. On Irish affairs the influence of the woman he had married in 1805 – Henrietta Frances Cole, fifth daughter of the 1st earl of Enniskillen (1736–1803) and sister of one of the leading Orangemen of the day – helped to transform his views. From his correspondence with Peel, de Grey emerges as a man of very set ideas, anxious to keep as much authority in his own hands as possible. In constant conflict with the more liberal chief secretary, Lord Eliot (qv) (as Earl St Germans to serve as lord lieutenant 1853–5), he opposed the appointment of catholics to any official position and had no sympathy for Peel's increasingly cautious and restrained attitude towards Irish affairs. His determined language at once masked and took its rise from an increasing panic at what he perceived to be the seemingly inexorable rise of catholic influence in all spheres of political life both at home and abroad.
The simultaneous presence in Ireland of an active and opinionated viceroy and an active (if not always efficient) chief secretary brought into the open the potentially explosive difficulties caused by the complex relationship between the two offices, a relationship left damagingly undefined at the time of the union. By December 1842 Peel was driven to comment that he feared that there would soon emerge ‘decisive proof that the government of Ireland cannot be satisfactorily administered under the present constitution’ (to Graham, 15 December 1842, Peel papers, BL, Add. MS 40448). De Grey's own state of mind is revealed in a letter of 6 May 1843 (Peel papers, ibid.) in which he urges Peel to ‘let no morbid sensitivity or mawkish apprehension . . . be allowed to weigh’ against the deployment of ‘unequivocal, full and determined resolve . . . by the law only as it exists, if you can, but by any extension of it which the repealers may force upon you’. Soon he was demanding that ‘disloyal’ magistrates – a group he reckoned too numerous to count – be summarily dismissed. Indeed, by February 1844 the difficulties created by the tensions between de Grey and Peel, let alone Eliot, had driven the prime minister to write to Lady de Grey (29 February 1844, Peel papers, BL, Add. MS 40540) in a vain attempt to mollify her (and, he hoped, her husband's) Orange proclivities by pointing out that three-quarters of the Irish people professed ‘a faith identical with ours in all the great truths of Christianity (the divinity of Our Lord, the doctrine of the Trinity, the doctrine of the atonement)’ and that this was indeed the religion ‘of more than one half of Christendom’. His pleas had absolutely no effect.
Eventually de Grey's undoubted ill health provided the opportunity for a tactful resignation in the summer of 1844, after which Peel's developing Irish policy of moderate ‘concessions’ on Maynooth, charitable bequests, and university education fell into the administrative hands of the more coherent duo of Eliot and de Grey's successor, the diplomat Lord Heytesbury (qv).
After 1844 de Grey played little part in public life. In 1845 he published a life of the royalist Sir Charles Lucas d. 1648, and in 1853 Characteristics of the duke of Wellington apart from his military talents. He died 14 November 1859, his wife having died 2 July 1848.