Breathnach, Cormac (Charlie Walsh) (1885–1956), politician and president of the Gaelic League, was born in Iveragh, Co. Kerry, son of Seán Breathnach, farmer, and Cáit Breathnach (née Chonchubhair). Educated at the national school in Ballinakilla, Co. Kerry (where he was a monitor), he qualified as a national school teacher from the Marlborough Training College in Dublin. A fluent Irish-speaker, he was engaged by the Gaelic League to teach Irish in rural districts of Co. Tipperary. Among his students were Dan Breen (qv), Seán Treacy (qv), Dinny Lacey (qv), and Seán Hogan (qv). Breen recalled that Breathnach often departed from the official text books to tell them of ‘the penal laws, the systematic ruining of Irish trade, the elimination of our native language, [and] the ruthless manner in which Irish rebellions had been crushed. . . . To the end of his days Charlie was in the habit of boasting of his rebel past pupils’ (Breen, 21). During these years he became an active member of the Irish National Teachers Organisation, and was unanimously elected its president in 1920, and again in 1932. In 1922 he played an important part in preparing the way for the introduction of Irish as a compulsory subject in primary schools. He became president of the Gaelic League (1926–8) and advised that William Gibson (qv), 2nd Baron Ashbourne, should succeed him.
In 1929 Breathnach published Field and fair: travels with a donkey through Ireland, the English translation of Pádraic Ó Conaire's (qv) Crann Geagach. Between 1920 and 1931 he wrote many articles for various Irish papers and was an editor of An Claidheamh Soluis. After chairing the international conference on education in 1933, he received the degree of LLD from the NUI. In that same year he was a founder member of the Educational Building Society and became one of its first directors. He also spent many years as chairman of the Dublin vocational education committee.
In 1926 he helped establish the Fianna Fáil party and was a member, and later chairman, of its national executive. He was elected Fianna Fáil TD in 1932 for Dublin North-west, and held the seat until his retirement in 1954. In the 1948 and 1951 elections he stood against his brother Fionán, who was a candidate for Clann na Poblachta. He was also a Fianna Fáil member of Dublin corporation (1933–54), and in 1949 was elected lord mayor. A keen golfer and a member of Clontarf Golf Club, he also maintained a great interest in the GAA.
He married first Kathleen Ryan, who died young; they had two children, one of whom, Seán Breathnach, became a district judge. He later married Bríd Prendergast, school principal, and lived most of his life in 384 Clontarf Road, Dublin, until his death on 29 May 1956.