Only the Prince Regent, that most extravagant and eccentric of monarchs, could have conceived a building like the Pavilion in Brighton.

And only John Nash, leading architect of the era, could have made the Prince’s fantasy a reality that still delights people today.

Nash was already friendly with the Prince when he was asked to transform the Marine Pavilion into an extraordinary palace. Indeed it was rumoured that his wife had once been the monarch’s mistress.

His large volume of work included many conventional country houses and grand terraces in London including Regent Street and houses fronting Regent’s Park. But his best known work of all was Buckingham Palace.

In the 1990s, Prince Charles introduced a volume of Pavilion prints by Nash by saying his ancestor was the greatest builder and collector his family had ever produced.

He added: “To understand the Prince Regent fully, and his contribution to the taste we rightly call Regency, we have to go to Brighton.

“The gradual transformation of Henry Holland’s polite marine villa into John Nash’s wild oriental fantasy – a riot of verandas, onion domes and minarets – echoes his own escape from the restricting conventions of his time to an exotic new world of the imagination.

“Besides his infallible eye for works of art, he could also spot the architects, artists and craftsmen capable of making these dreams a reality.”

When the finishing touches were being made to the Pavilion in 1823, the monarch, now King George IV, cried with joy at its splendour.

But he was becoming old and ill – he seldom visited the Pavilion when complete and died in 1830.

His brother, William IV, showed little interest in the palace and Queen Victoria later sold it to the Brighton authorities at a knockdown price.

Architectural expert Gervase Jackson-Stops said few buildings more vividly recalled the character of their creator than the Pavilion.

He said the greatest of Regency follies occasionally verged on the absurd but redeemed itself by reflecting the Prince’s charm and intelligence.

It was Nash who added the magnificent Music Room at one end of the original building and the Banqueting Room at the other before embellishing the roof with a forest of domes and pinnacles.

Jackson-Stops added: “The resting skyline, audacious and improbable, gave a picturesque unity to the whole building.”

Nash was already over 60 when asked by the Prince to undertake his Brighton commission. He had then been employed by him for five years and this was virtually a full-time post.

But after George IV died, Nash was left without a patron and was made to shoulder some of the blame for gross overspending on Buckingham Palace. He moved to the Isle of Wight, not far from Queen Victoria in Osborne House, and died at Cowes in 1835.

He never received the knighthood awarded to many lesser architects and the Pavilion fell out of fashion for a century. But it is now recognised as a wonderful fantasy and Nash is remembered as the pre-eminent architect of Regency England.