Brooke, Francis Theophilus (‘Frank’) (1851–1920), land agent and railway executive, was born in 1851, the youngest of the five sons of George Augustus Frederick Brooke DL (1805–74), of Ashbrooke, Co. Fermanagh, and Lady Arabella Georgina Brooke (d. 29 January 1899), the daughter of Hans Francis Hastings, twelfth earl of Huntingdon. Educated at a private school, he joined the Royal Navy in 1865 and retired with the rank of lieutenant in 1877 to become a land agent on several large estates in counties Fermanagh, Longford, and Leitrim. He was active on behalf of the landlords in the land war of the 1880s and became a magistrate for Co. Fermanagh in 1885; in the general election in December of the same year he unsuccessfully contested Fermanagh South as a conservative/unionist candidate. After the election he rejuvenated the constituency organisation and became the first chairman of South Fermanagh registration committee and a member of the Orange Order.
In January 1886 Brooke declared: ‘we will meet every rebel demand, first with every legal and constitutional means to uphold the integrity of the empire. Second, should this course fail and the people of England refuse to hear our cry, then we men of Ulster will meet our enemies with rifles in our hands’ (Fermanagh Times, 11 Jan. 1886). The lord chancellor rejected appeals to have him struck off the commission of the peace for expressing such sentiments. Again unsuccessful in the general election of July 1886, Brooke departed Fermanagh three months later to become land agent on Lord Fitzwilliam's estate at Coolattin Park, Shillelagh, Co. Wicklow. In 1876 the estate comprised some 91,748 acres across counties Wicklow, Kildare, and Wexford.
A director of the Dublin and South Eastern Railway (1898–1920), Brooke succeeded F. W. Pim (qv) as chairman (1917–20). He was also chairman of the National Bank and the Irish branch of the Norwich Union Society, a commissioner of Irish Lights, a very active steward of the Turf Club (1911–20), chairman of the Irish national war memorial committee, and JP and DL of counties Fermanagh and Wicklow. Sworn of the Irish privy council in 1918, he was a personal friend of Lord French (qv). A regular attendee at vice-regal dinners, in 1918 he was appointed to the much criticised Lord Lieutenant's Advisory Council.
On 20 June 1877 Brooke, a cousin of Sir Victor Brooke, third baronet, married Alice Mary (d. 1909), the daughter of the Very Rev. W. Ogle Moore, dean of Clogher. They had two sons and one daughter. On 3 May 1913 he married Agnes Letitia, the second daughter of Frederick D. Hibbert of Chalfont Park, Buckinghamshire, England. The family lived at Ardeen, Shillelagh, Co. Wicklow.
On 30 July 1920 Brooke was shot dead by three men while sitting in his office at Westland Row railway station, Dublin. The motive is unclear, but may have been related to his membership of the Irish privy council and his friendship with Lord French. In 1918 Robert Barton (qv) went on trial for a number of matters, including making a statement that ‘if [Tom] Fleming gets the same treatment in gaol as Shaun Etchingham (qv) we will take reprisals on Lord French and Frank Brooke. If anything happens we will give them a touch of Tipperary medicine’. The murder has also been attributed to Brooke's role in the industrial unrest caused by the railway workers’ refusal to carry munitions in May 1920. H. B. C. Pollard (d. 1966) believed that it was probably the work of a small ex-citizen army group within the IRA. After he had received threatening letters Brooke had been under police protection, and at the time of his death was carrying a loaded revolver.