When Kit Harington was a schoolboy in Martley, Worcester, in the late ’90s, he liked to tell friends the truth about Bonfire Night. It wasn’t Guy Fawkes, he’d say, who was the brains behind the Gunpowder Plot of 1605. It was a devout Catholic from Warwickshire called Robert Catesby.

He was the one who devised the plan to blow up Parliament, wipe out King James I and, in so doing, the ruling Protestant elite. Guy Fawkes was just one of the plotters. The question of why Fawkes is etched into the mythology of 5 November, and not Robert Catesby, is a personal one for Harington: he is a distant relative.

‘My middle name is Catesby and it’s something I was proud of,’ he says. ‘It’s a part of my family history.’

Harington went on to find fame as Jon Snow in the HBO series Game of Thrones (where he also met fiancée Rose Leslie; the couple announced their engagement last month). But he never forgot his relative. And now, more than 400 years after his death, Harington has, in his own way, led a campaign to ensure that we don’t either.