Cooper was born at Lough Park, co. Westmeath, a descendant of Edward Cooper, a Cromwellian soldier who had settled in Ireland and ‘became possessed of a great estate in that kingdom’.
Cooper was a career officer who joined the army in May 1845, and served latterly with the Grenadier Guards, attaining the rank of lieutenant-colonel in November 1857. He married in 1858 and in April 1863 inherited an estate of more than 35,000 acres at Markree Castle, co. Sligo, from his uncle Edward Joshua Cooper (1798-1863), Conservative MP for County Sligo, 1830-41, 1857-9.
As the largest landowner in the county, and one who annually drew more than £10,000 from his estate, Cooper’s influence in Sligo was thought to be considerable.
In January 1866 Cooper joined a deputation to the Irish chief secretary to request that the costs borne by Irish poor law unions for medical and educational purposes be met from the consolidated fund.
Above all, Cooper was strongly opposed to the disestablishment of the Irish Church, bringing up petitions in its defence, 9 Apr. 1866, 30 Mar. 1868.
Although Cooper retained the confidence of Sligo’s Conservatives, he was not popular in his own neighbourhood, where he had made an unsuccessful attempt to impose a code of rules and regulations on his tenants. At the 1868 general election he was pelted with stones during his canvass and shouted down at the hustings.
Cooper did not seek election again, but nominated his former colleague, Sir Robert Gore Booth, at Sligo in 1874.
Cooper’s wife, who sat on the Ladies’ Grand Council of the Primrose League from 1894, died in January 1902, four weeks before Cooper’s death at his London residence in Portman Square following a long illness.
