Ardal O'Hanlon was born on 8 October 1965 in Carrickmacross , County Monaghan , the son of politician and doctor Rory O'Hanlon and Teresa Ward . He has five siblings . The episode of '' Who Do You Think You Are ? '' which aired on 6 October 2008 revealed that O'Hanlon 's paternal grandfather , Michael O'Hanlon , was a UCD medicine student who had joined the IRA during the Irish War of Independence and was a member of Michael Collins 's squad which assassinated British secret service agents on the morning of Bloody Sunday . Details of his grandfather 's activities survive in UCD Archives , as well as Blackrock College . It also transpired that , on his mother 's side , he is a close relative of Peter Fenelon Collier
Bloody Sunday
Bloody Sunday (1920)
Ardal O'Hanlon