O'Donovan led or participated in many daring raids against British forces in County Cork, including the capture of Blarney's Royal Irish Constabulary barracks on 1 June 1920.
O'Donovan was also in command of the six-man IRA unit that carried out the assassination of RIC District Inspector Gerald Bryce Ferguson Smyth at the Cork and County social club on the evening of 17 July 1920.
[2] Some weeks earlier Smyth had gained notoriety when RIC Constables in Listowel, County Kerry mutinied rather than listen to his orders to "shoot to kill" all persons who were suspected of Irish republicanism.
He was also involved in the seizure of a large cache of guns and ammunition from the British Royal Navy tender, Upnor, off the coast of County Cork, after first commandeering a smaller vessel at Queenstown.
During the aftermath of the Civil War, in return for badly needed funding, the IRA's intelligence arm covertly acquired classified information in both Great Britain and the United States of America, which was then sold to the Soviet Union.
[8] Also according to Mahon and Gillogly, "Mr. Jones" was also involved in efforts to acquire the ability to build chemical weapons for both the GRU and for the IRA, which hoped to use mustard gas against the military and police forces of the Irish Free State.