Conor was born in the fictional town of Ballyutogue in County Donegal in 1873. He grew up there, working his family's farm land with his father Tomas.
Much to the disappointment of his father Tomas, Conor became an apprentice to the town blacksmith. He later moved to Derry where he opened his own Forge. Conor stayed in Derry until the Witherspoon & McNabb Shirt Factory, the town's major employer, caught fire, resulting in the deaths of several close friends including Maude McCracken. Conor left the Bogside of Derry to play rugby for Sir Frederick Weed's Belfast Boilermakers and to work for Long Dan Sweeney and the Irish Republican Brotherhood (IRB).
In Derry Conor became associated with the revival of Gaelic culture, particularly through the Gaelic League and Gaelic football. There he became a part of the fledgling Irish Republican Brotherhood. The Irish Republican Brotherhood was exporting guns to a headquarters by train for many months, while playing rugby for the Belfast Boilermakers. During their last shipment of over 1,000 guns at Six-mile-cross, Conor and the Brotherhood were caught and imprisoned. Conor was held in prison for numerous felonies for over a year until he escaped with the help of his brother who was a priest and a sympathetic Catholic prison guard. Conor immediately continued his work for the Brotherhood including gaining American support, training men, and planning raids on British and loyalist buildings
Conor continued his Republican activities with the Brotherhood, until he eventually led an assault on a castle where loyalist paramilitaries were storing a large cache of weapons. As they met unexpected resistance from the British, Conor was forced to set off the charges, thus sacrificing his lifelong friend, Seamus O'Neill, who was acting as the rear guard. Conor decided, against his original plan, to stay behind and man a machine gun with his aging commander Dan Sweeney. After being badly wounded by British forces pursuing the raiding party, he was killed with a bullet to the head by a British officer whose group found him. About to call a stretcher, the officer noticed that "half his guts are on the floor", and put the beast down. He died knowing his mission was a success and with the name "Atty" (the woman he was romantically involved with immediately prior to the raid) on his lips.