Deasy, Liam (1896–1974), IRA officer and author, was born 6 May 1896 at Kilmacsimon Quay, Bandon, Co. Cork, third among six sons of William Deasy, seaman, and Mary Deasy (née Murray). He was educated locally at Ballinadee before leaving school at 13 to work in nearby Bandon. Although an active member of the Gaelic League and the GAA, he did not join the Volunteers until after the 1916 rising but quickly became a key member of the Bandon company and in late 1917 was sworn into the IRB by Thomas Hales (qv). In May 1918 he formed a new Volunteer company at Innishannon, based around his old football team, Valley Rovers, and became its captain. His organisational ability and efficiency in procuring arms led to his promotion to adjutant of the Bandon battalion in December 1918, and he was appointed adjutant to the newly formed Third Cork Brigade in August 1919. He lost his job in a Bandon timber yard after an RIC raid on the premises in November 1918 and remained on the run as a full-time IRA organiser until the truce in 1921. He was actively involved in planning IRA raids on enemy forces from late 1919 onwards and from November 1920 was regularly a part of the brigade's flying column under Tom Barry (qv), seeing action at Toureen, Bandon, and Crossbarry. On 28 November 1920 his younger brother, Patrick Deasy (b. 1904), was killed during the Kilmichael ambush. After the death of Charlie Hurley (qv) in March 1921 Deasy was elected commanding officer of the Third Brigade and held this position until the truce.
Although he admitted that the early months of 1921 had been difficult for the IRA, the major engagement at Crossbarry convinced him that the IRA could have continued the war successfully and he thus greeted the truce with some scepticism. Promoted to adjutant of the 1st Southern Division under Liam Lynch (qv) shortly after the truce, he continued to prepare for a renewal of hostilities, convinced that the British would not agree to a republic but unable to believe that the political leadership would accept anything less. He was thus deeply disappointed by the terms of the treaty and the dáil's subsequent acceptance of it, but throughout the early months of 1922 remained convinced that civil war could be avoided. Elected to the executive of the IRA in March 1922, he became commander of the entire 1st Southern Division when Lynch took on the role of IRA chief of staff, but (with more hope than judgment) made few preparations for the coming conflict. Although a moderate on the anti-treaty side and critical of the seizure of the Four Courts, he reluctantly decided to fight after the provisional government forces began their bombardment, and left Dublin immediately with Lynch to organise resistance in the south. He later strongly rejected the assertion by Eoin O'Duffy (qv) that he and Lynch undertook to stay out of the conflict in order to secure their release when they were briefly detained by him on their journey south. Ambivalent about the war from the beginning and limited by the cautious Lynch, Deasy failed to take aggressive action in the early stages of the war and thus helped squander the anti-treaty forces’ early advantages in Munster, most obviously through his evacuation of Buttevant barracks in Cork without a fight. Demoralised after the fall of Limerick and Cork, and unable to exert effective control over his individualistic local officers, he realised by August 1922 that the anti-treaty position was hopeless, but continued to plan a guerrilla campaign and organise local resistance in Munster until the end of the year. He was present, and inspected the ambush position, at Béal na Blath on the day Michael Collins (qv) was shot, although he was not present during the ambush itself. In failing health and deeply distressed by the assassination of his friend Sean Hales (qv) and the subsequent execution of the republican leaders from the Four Courts, he was captured in arms at Tincurry on 18 January 1923 and imprisoned in Clonmel. Sentenced to death by the Free State government, he successfully requested a stay of execution to appeal to his comrades to end the war, convinced that further bloodshed was futile. Although his appeal was unsuccessful, and he was heavily criticised by some of his former comrades for what they considered a betrayal of his beliefs in the face of imminent execution, it had a demoralising effect on the anti-treaty forces. In 1924 he was court-martialled and expelled by the IRA for launching the appeal.
In 1924 he returned to Cork, where he set up a successful business, Ideal Weatherproof Ltd, which manufactured waterproof textiles. On 26 June 1940 he enlisted in the Irish army and rose to the rank of commandant, later joining GHQ in Dublin and helping to organise the Local Defence Forces. He returned to his business in 1945 and was later managing director of Trimproof Ltd. After his retirement he spent much of his free time writing his memoirs, and in 1973 these were published as Towards Ireland free. The book, which was highly successful, provoked a furious response from Tom Barry, who claimed that Deasy's account, particularly of the controversial Kilmichael action (in which Deasy's younger brother had been killed), was inaccurate. Barry's critical pamphlet The reality of the Anglo-Irish war, 1920–21, in west Cork was published just after Deasy's death, but Deasy's account was supported by the majority of the surviving Cork IRA men. A second volume of his memoirs on the civil war was published posthumously under the title Brother against brother. He died 20 August 1974 at St Ann's hospital, Northbrook Road, Dublin.
He married (24 November 1927) Margaret Mary O'Donoghue of Clonakilty, Co. Cork; they had three daughters.