Watch Who Do You Think You Are? Season 15 Episode 3 Online

Comedian Lee Mack was born Lee McKillop in the north of England, just like his McKillop great-grandfather, who was also a comedian, known as Billy Mac. Lee has a few playbills from Billy Mac's variety hall performances, but knows little more about him. Not long into his journey, Lee discovers that his great-grandfather was passionate about more than making people laugh. Billy Mac joined the first ever pals battalion in Liverpool at the start of the First World War and honed his act at the front lines in the Battle of the Somme. Lee is also curious about his maternal grandad Joe's upbringing - deserted by his unwed mother and raised by his grandparents in County Mayo at the time of the Irish Civil War.