Northumberland Duke moans that his family have been imprisoned in their castle by hordes of curious Harry Potter and Downton Abbey fans 

It all started with residents of the 'unremarkable' village of Kidlington in Oxfordshire wondering why coachloads of Chinese tourists were poking around their gardens.

But now the blue-blooded Duke of Northumberland is getting in on the act too, and moaning that his family have been imprisoned inside their 11th-century castle by nosy Harry Potter and Downton Abbey fans.

Ralph Percy said his wife and four children are unable to enter or leave 150-room Alnwick Castle without meeting crowds of tourists, forcing them to stay inside, reports the Daily Mail

Tired of being confined to the castle keep, the family have chosen another home in the Scottish borders as their summer residence.

Alnwick Castle featured as Hogwarts in the first two Harry Potter films and as Brancaster Castle in Downton Abbey's 2014 and 2015 Christmas specials. 

It now attracts upwards of 250,000 visitors per year, something that it posing problems for the Eton and Oxford-educated 12th Duke. 

He told the September issue of Tatler: 'It didn’t really work because we couldn’t get in or out without going through crowds.

“And because we lived in the keep, there were no private gardens, so the children just ended up staying inside the whole time.”

But the Duke, who is thought to be worth £350 million and inherited his title in 1995, can be reassured that Alnwick Castle's fame is reeling in plenty of cash.

In 2014, day-visit spends from tourists interested in its film and television history was estimated to be worth £4.3m. 

He told the September issue of Tatler: 'It didn’t really work because we couldn’t get in or out without going through crowds.

“And because we lived in the keep, there were no private gardens, so the children just ended up staying inside the whole time.”

But the Duke, who is thought to be worth £350 million and inherited his title in 1995, can be reassured that Alnwick Castle's fame is reeling in plenty of cash.

In 2014, day-visit spends from tourists interested in its film and television history was estimated to be worth £4.3m.