Byrne, Christopher Michael (‘Christy’, ‘C. M.’) (1886?–1958), politician, farmer, and auctioneer, was born in Blackrock, Co. Dublin, the only child of Walter Byrne of 13 Temple Road, Blackrock, and Ballykillavane, Glenealy, Co. Wicklow. Educated (1895–8) at Blackrock College, he became involved in politics at an early age through the GAA, Gaelic League (1905), and Coiste Conndae (1906). An ardent Parnellite, he became the youngest councillor in Ireland when he was elected to succeed his father on Blackrock urban council. He retired from the council on moving permanently to Ballykillavane.
In 1913, without any authority, he started to organise the Irish Volunteers in Co. Wicklow. He attended the funeral of O'Donovan Rossa (qv) in August 1915 with contingents of Volunteers from Wicklow. In autumn 1915 he was involved in the short-lived Co. Wicklow Rifle League, and the following year began purchasing arms under orders from Michael Fleming of Drumcondra. As he was quartermaster of the Wicklow Brigade of the IRA, his home was repeatedly raided by British forces.
In 1918 he acted as director of elections for Sean R. Etchingham (qv) in Wicklow East, and the following year (1919) became a member of Rathdrum board of guardians and chairman of Rathdrum district council. Elected to Wicklow county council (1920), he was one of the trustees of the council's funds under the dáil Department of Local Government and succeeded R. C. Barton (qv) as county council chairman, serving for seventeen of the years between June 1922 and 1945. Deeply involved in local administration in Wicklow, he served as chairman of the Wicklow county committee of agriculture (September 1921–October 1950), the technical instruction committee (and later the county VEC), Grangegorman mental hospital (1925–31), and Wicklow harbour commissioners. A member of Wicklow county council c.1920–1958, he represented Wicklow on the general council of county councils for more than a decade. One of the most prominent figures in Co. Wicklow for fifty years, he was assiduous in forwarding schemes for the improvement of hospitals, the erection of cottages, the provision of water and sewerage supplies, and generally improving the lot of the working classes. For a time he was a partner in the auctioneering firm of Clarke & Byrne of Wicklow town.
In addition to his prominence within Wicklow, he played a significant role in national politics, beginning with his election as a Sinn Féin TD for Kildare–Wicklow (1921–3) in 1921. A supporter of the treaty, he was reelected to the dáil in 1922 for Kildare–Wicklow and again in 1923 as a Cumann na nGaedheal TD for Wicklow (1923–7). A member of the commission on agriculture (1922), in 1924 he served a period as acting party whip. Disillusioned by the government's acceptance of the report of the boundary commission (1925), he left Cumann na nGaedheal in 1926 and was involved in forming a new party, Clann Éireann, with Pádraig Ó Máille (qv). He stood as an independent candidate in the general elections of 1927 and 1932, but was unsuccessful and later joined Fianna Fáil. Failing to secure a dáil seat for the party in 1937, he was elected to the seanad in 1938 on the administrative panel and held the seat until 1943, when he was again elected to represent Wicklow in the dáil. However, his success was short-lived and he was defeated in both the 1944 and 1948 elections. His dáil contributions dealt in the main with constituency matters and agriculture and fisheries (1922–7). He was a member of the Fianna Fáil national executive in the 1940s.
In his youth he was a noted long-distance cyclist. A member of the Ashford GAA club, he distinguished himself in administration rather than as a player. The club's delegate to the county convention in Aughrim in 1907, he was the Leinster council representative on the central council (from 1908) and chairman of the Wicklow county board 1931–54. He actively promoted the playing of camogie and helped organise Feiseanna and other cultural events. A devout catholic, he had a mild and unassuming manner. Near the end of his life he suffered from senility and entered St John Of God Nursing Home, Stillorgan, Co. Dublin, where he died 12 April 1958.
He married (3 June 1919) Lucy Florence, daughter of Laurence Cullen and Julia Cullen (née Ryder), farmers of Rathmore, Ashford, Co. Wicklow. They lived at Ballykillavane, Glenealy, Co. Wicklow, and had no children. Lucy was active in many nationalist organisations and their home was often a rallying point for those organisations. Her sister Julia was married to Michael Staines (qv), TD, while Byrne was a relative of the publican Davy Byrne of Duke St., Dublin.