Cavendish, Spencer Compton (1833–1908), 8th duke of Devonshire , chief secretary for Ireland, liberal unionist leader, was born 23 July 1833 at Holker Hall, Lancashire, England, eldest among three sons of William Cavendish, later 7th duke of Devonshire, and his wife Lady Blanche Georgiana Howard, daughter of George Howard, 6th earl of Carlisle. He attended Trinity College, Cambridge, and in 1854 graduated MA. Styled Lord Cavendish (1834–58) and marquess of Hartington (1858–91), he was elected liberal MP for North Lancashire in 1857, became secretary of state for war (1866) and was postmaster general (1868–71). He eventually owned estates of 32,550 acres in Co. Cork and 27,488 acres in Co. Waterford, and a residence at Lismore Castle, Co. Waterford. In December 1868 his support for church disestablishment in Ireland briefly cost him his parliamentary seat. Although wary of any interference with private property, he accepted Gladstone's 1870 land act (which legalised customary tenant right), as a compromise to ward off a broader attack on property rights. The support of a great Anglo-Irish landowning magnate was crucially important for Gladstone in passing the act. Hartington declined the lord-lieutenancy of Ireland in 1869, although in December 1870 he very reluctantly accepted the chief secretaryship with a seat in cabinet and was sworn in 12 January 1871.
Since Hartington was in the cabinet and the lord lieutenant, Spencer (qv), was not, there was considerable scope for discord among them, but the two men worked well together, perhaps helped by being second cousins and sharing a love of hunting. Hartington represented to the cabinet Spenser's demand for the suspension of habeas corpus to put down persistent agrarian violence in Co. Westmeath and surrounding districts. Gladstone was reluctant to grant such sweeping powers and referred the matter to a commons select committee. Its recommendations were enshrined in the ‘Westmeath act’ of June 1871 which allowed detention without trial for those suspected of agrarian offences. Hartington was also instrumental in preventing a great Fenian amnesty demonstration in the Phoenix Park, scheduled to coincide with the visit of the prince of Wales in August 1871. He was also responsible for more conciliatory measures: believing that most Irish voters were governed either by the landlord or the priest, he introduced the ballot act (July 1872), which instituted secret voting throughout the UK. He also pressed for the nationalisation of Irish railways to encourage economic development, but received little support from his colleagues.
He disagreed with Gladstone's proposal in 1873 to turn the University of Dublin into a national university which would incorporate TCD, the queen's colleges, and the Catholic University, correctly foreseeing that the measure would satisfy no one. Suspicious of catholic designs on education, Hartington greatly offended catholic sensibilities by claiming that the catholic clergy wanted absolute control over education in Ireland. He openly expressed his opposition to the university bill in cabinet and threatened to resign. In March 1873 the bill was defeated, greatly damaging Gladstone's authority, and the liberals fell from power in February 1874. The final months of Hartington's tenure as chief secretary saw the emergence of the Home Rule League, which he strongly opposed, and he predicted that home rule would eventually split the liberal party.
During his leadership of the liberals in opposition (1875–80), relations with Irish home rulers were strained; he was particularly appalled by the obstructionist tactics adopted by militant Irish MPs. After the liberal return to government he was secretary of state for India (1880–82) and war (1882–5). The party's foremost whig patrician, he was suspicious of democracy and acquiesced reluctantly in the extension of the franchise in 1884–5, especially with regard to Ireland. In general, his views on Irish questions differed markedly from Gladstone's: he believed the liberals should not make any concessions to secure Irish support in parliament and he strongly disapproved of the negotiations with C. S. Parnell (qv) in April 1882 which led to the ‘Kilmainham treaty’. His support for coercive legislation for Ireland was strongly reinforced by the assassination on 6 May 1882 of his younger brother, the newly appointed chief secretary, Lord Frederick Cavendish (qv), whose loss he felt keenly. He opposed Gladstone's proposals for a local government bill for Ireland in 1883, arguing that Irish nationalists would use local authorities to bolster their campaign for home rule, and accused Gladstone of wishing ‘to hand over the government of Ireland to the Fenians’ (Jenkins, 179). He believed that moderate liberals and tories had much in common and should unite against Irish nationalists, whom he regarded as dangerous enemies of the British constitution.
His staunch opposition to Irish self-government led him to vote with the conservatives to defeat the first home rule bill in June 1886, and he assumed the presidency of the Liberal Unionist Association (1886–1904). He declined the premiership in July and December 1886, but as leader of the liberal unionists gave independent support to the conservative government and invariably agreed with Salisbury's Irish policies. He became 8th duke of Devonshire (1891) and in 1893 moved the rejection of the second home rule bill in the lords. In 1895 he became lord lieutenant of Co. Waterford, and was lord president of the council (1895–1903) in the conservative-led government.
Described as ‘hard-working, conscientious [and] stolid’, he had a reputation for pragmatic common sense but was also said to be ‘innocent of the slightest spark of humour, guiltless of gracefulness of diction, and free from the foible of fanciful thought’ (G.E.C., 351). His manner was stiff and aloof; he greatly disliked public speaking and was extremely cautious, usually raising objections to any new proposals. He regularly complained of being tired of and disgusted with politics and was glad to retire in 1903. He died at Cannes, 24 March 1908, and was buried at Edensor, near Chatsworth.
He married (1892) Louise, daughter of Count von Alten of Hanover, and widow of William Montague, 7th duke of Manchester, with whom he had conducted an adulterous affair since the early 1860s; she was known as the ‘double duchess’. They had no children.