Somerville, Sir William Meredyth (1802–73), chief secretary for Ireland (1847–52), was eldest son of Sir Marcus Somerville (c.1772–1831), politician and 4th baronet, and his first wife, Mary Anne, daughter of Sir Richard Meredith of St Katherine's Grove, Co. Dublin. Sir Marcus was briefly a member of the last Irish parliament and sat in the union parliament for Meath (1801–31) as an independent. For a decade he sided with the opposition (except during the brief ministry of Grenville and Fox, February 1806–May 1807), though his support was not particularly vocal. The regency effected a change in his politics; thereafter he was frequently found in the government lobby, though he invariably voted for catholic relief. He died while still a sitting member on 11 July 1831.
William matriculated at Christ Church, Oxford, in February 1822 but did not graduate. He was a paid attaché at the British embassy in Berlin (1829–32), after which he sought a political career, standing unsuccessfully as a liberal for Wenlock in January 1835, and two years later being returned as liberal member for Drogheda (1837–52). He was from his earliest parliamentary days almost entirely preoccupied by Irish, and especially farming, matters. A humane landlord who endorsed tenant right on his own Meath estates and was held up as a model by the Dublin University Magazine, he agitated strongly for the repeal of the corn laws in 1841. He was a friend of the Young Irelander William Smith O'Brien (qv) and was initially sympathetic to some of his views on Ireland, but was always more cautious: in 1843 he told Smith O'Brien that his ‘Remonstrance to the people of Great Britain’, which listed Irish grievances, was an excellent document but would do no good, and he refused to sign it. However, he and Smith O'Brien joined forces to bring forward motions from 30 March 1846 to prevent the Peel government from postponing the corn bill and bringing in a coercion bill; their efforts were rewarded on 14 June by the defeat of the coercion bill and the overthrow of the tory government.
In the new administration Somerville became under-secretary of state at the home department, and a year later (22 July 1847) was made chief secretary for Ireland and appointed to the privy council. He took office at a thankless time; the famine was at its height and the relief of it was not within his power. He did not underestimate the crisis and strongly petitioned the government for intervention aid, but to little effect. He introduced on 15 February 1848 a landlord and tenant bill which went some way towards compensating tenants for improvements but it had been much amended at an early stage and was a failure. Smith O'Brien dismissed it as a sham manoeuvre, and the government failed to back it. Somerville referred the bill to committee, where a number of alterations were made before it was dropped. In May 1850 the government considered, only to quickly abandon, the notion of reviving it. However, Somerville had the triumph that year of guiding through parliament a long-awaited measure, the Irish franchise act, which increased the electorate from 45,000 to 165,000, and has been termed ‘the single most important legislative influence on . . . the course of elective politics in nineteenth-century Ireland’ (Hoppen, 17). It based the franchise on the occupation, rather than ownership, of property and made voter registration a matter of automatic renewal.
Somerville was sufficiently in the O'Brien family's confidence to have been privy to Sir Lucius O'Brien's concerns about his brother in the months before the 1848 Young Ireland Rising. His close friendship with Smith O'Brien possibly explains why he took so little part in the suppression of the rising, which was dealt with by the viceroy, Lord Clarendon (qv).
On Russell's ministry falling in February 1852, Somerville ceased to be chief secretary and at the general election in July was defeated in Drogheda by the independent candidate, James McCann. After a two-year parliamentary absence he was returned at a by-election for Canterbury in August 1854. From this constituency he continued to agitate on Irish matters, coming out strongly in 1856 in favour of the Irish labourers bill, and the following year supporting a motion for the abolition of the Irish viceroyalty. In 1859 he brought in a bill enabling catholics to be appointed to the Irish chancellorship, which was supported by the leaders of both parties but after reference to a committee was withdrawn.
Somerville was raised to the Irish peerage with the title Baron Athlumney of Somerville and Dollardstown on 14 December 1863, and three years later (3 May 1866) was made a peer of the UK as Baron Meredyth of Dollardstown, Co. Meath. In his last speech to the commons (21 June 1864) he declared himself against any further legislative interference between landlord and tenant; in keeping with this, from the lords he voted against Lord Clanricarde's 1867 bill to simplify tenure of Irish land, declaring that he preferred even emigration to legislative interference. However, he supported Gladstone's 1870 land act, as he did the 1869 Irish church disestablishment bill. He died at Dover on 7 December 1873 and was buried in Meath.
He married first (22 December 1832) Lady Maria Congynham (d. 1843), youngest daughter of the 1st Marquess Conyngham; they had a daughter. His second wife (m. 16 October 1860), Mary Georgiana, daughter of Herbert Jones, sergeant-at-law, survived him, as did one son, who succeeded to his titles, and four daughters.