Bonneville says he has encountered many people who get caught up in the series when they only intended to watch a single episode.

“There’s a strange thing… a page-turning compulsion about it,” he says. “They’re still there at two in the morning because they’re hooked on it. People love watching whole seasons of it in one chunk.”

The actor says he himself was addicted from the moment he read the first script.

“By the end of it I had met about 16 characters who were all incredibly vivid in my head, which was quite rare,” he says. “They all had their own voice and, most importantly, I wanted to know what happened next.”

Bonneville is now instantly recognisable from his seven years playing the Earl of Grantham. So how, asks Charlotte Green, does he cope with the increased exposure the role has brought him?

“It goes with the territory and you just have to accept it,” he says. Bonneville cites fellow Downton actor Robert James-Collier, who told him, “The difference between American fans and British fans… In America they cross the road to tell you how much they love the show, and in Britain, they cross the road to tell you they don’t watch it.”

“I felt a real sense of ownership that Paddington was my pal and this was my world,” he says. “I have to say within a page of the script I had been drawn into the world that was created and I was laughing out loud and had a lump in my throat in all the right places.”