Julian Fellowes, who created hit period drama Downton Abbey, has revealed that he was taken aback by the huge success of the show.

Speaking to Radio Times, he said, “I thought we’d made a good show and people would enjoy it, but it was extraordinary.

“We were playing to something like a third of the adult population.

“I mean, nobody could expect that level of success, except for Simon Cowell.

“It was completely mad.”

Julian went on to reveal that the show has an unexpected mass appeal.

He said, “The demographics were very wide backgrounds, very wide social grouping, very wide age grouping and ethnic backgrounds…

“And I’ve had every type come up to me about ‘Downton’ – taxi drivers, shop assistants, not just people having lunch at Fortnums.”

The second series of Downton returns to our screens this Sunday, and Julian hasn’t ruled out the possibility of a third series.

He said, “Unless you have a nuclear bomb go off, there’s always an opening.”