Windsor Castle value

But the price tag is hardly surprising when you consider that the palace has 775 rooms, including 19 State rooms, 52 Royal and guest bedrooms, 188 staff bedrooms, 92 offices and 78 bathrooms.

It also has a cinema, swimming pool, 40 acres of land and it's very own post office.

A Zoopla spokesman said: "Everything has a price, even Buckingham Palace.

"And it shows that the Royals might be shrewder investors than they are given credit for, given that Buckingham House - as it was known then - was reportedly purchased for only £21, 000 by George III in 1761. He was clearly the Sarah Beeny property developer of his time."

The Queen's weekend retreat, Windsor Castle, has also been valued for the first time at £180 million. The figure takes into account the £37 million spent on restoration following the 1997 fire.

However, it seems that Royals do have something in common with other British property owners, and are not immune to the fall in the housing market.

Zoopla has estimated that Buckingham Palace has fallen in value by £57 million in the last 12 months, meaning it would have been worth £992 million.