Alo O'Brennan, Cormac St, Tullamore was a member of a strongly republican family. He served a month in jail for nationalist activity and the family home in Church St, Tullamore, was raided on a number of occasions. He was manager of the employment exchange in Tullamore from the late 1920s until 1974. Leading member of Irish National Forresters and a former Chief Ranger, he was a founder member of Tullamore Pipe Band in 1911. He died in 1976 aged 82.
Frank O’Brennan was born in Tullamore c.1985, the younger brother of Séamus and Alo O’Brennan. He was active in the Tullamore Volunteers from 1913 and is listed on the charge sheet of those present during the Tullamore Incident of March 1916, after which he was arrested and court-martialled in relation to the wounding of RIC Sergeant Ahearn. After his release in June 1916, he rejoined the Irish Volunteers and took part in the usual activities. In 1919 he watched the movement of British forces and carried dispatches. In June 1920 he was in charge of road blocking during attacks on Geashill and Clara Barracks, and was involved in an armed attack on British forces at Ballycommon Bridge in which a civilian was killed. He took part in three raids for mail. In the autumn of 1920 he brought Seán McGuinness and members of his Active Service Unit (Flying Column) from Kilbeggan to Geashill where they killed an RIC Head Constable, but O’Brennan took no part in the shooting. He died in 1964.
Maura O'Brennan, of Cormac Street, Tullamore, spent her early years in Wexford. She came to Tullamore in the early 1920s and was a member of the teaching staff of the convent national school, and except for a brief period in Mucklagh spent all of her teaching career in Tullamore. She married Alyosius O'Brennan in {??]. She was a founding member of Tullamore Guild ICA, and appeared as a guest of honour at the ICA 25th anniversary party in the Bridge House in May 1984. She died in July of that year, aged 79.