He was born the heir to a huge Mexican fortune, to parents of Basque origin, and a mother (Dolores de Yturbe), both of whose ancestors had migrated from Spain to Mexico in the 18th century.

[3] The family made its fortune there in silver, agriculture, and real estate but left Mexico after the execution of Emperor Maximilian in 1867.

It included an electronically operated hedge that parted to reveal a view of the Arc de Triomphe,[3] and a roof terrace designed by Salvador Dalí.

[6] In 1939 he acquired the Château de Groussay, at Montfort-l'Amaury (Yvelines), and spent the next 30 years improving its interiors and grounds and expanding the structure by adding extra wings.

But he had an enormous number of genuine pieces, such as an ebony and bronze Louis XVI desk once owned by Paderewski.

Beistegui was not troubled by the Germans during their occupation of France, because he had a Spanish diplomatic passport, and was treated as a citizen of a neutral country.

He did occasionally undertake commissions for others – salons in the Ministry of Foreign Affairs in Madrid, a suite of rooms at the Waldorf-Astoria Hotel in New York City, and the library at the British Embassy in Paris (with the designers Georges Geffroy and Emilio Terry) – but he used his artistic talents almost entirely for his own pleasure.

He purchased furnishings that had been acquired from the palazzo's less fortunate neighbours, and from the Duke of Northumberland bought eighteenth-century copies of frescoes by Raphael, Annibale Carracci, and Guido Reni.

On 3 September 1951 Beistegui held a masked costume ball, which he called Le Bal oriental, at the Palazzo Labia.

[2] Cecil Beaton's photographs of the ball are considered notable for capturing an almost surreal society, reminiscent of the Venetian life immediately before the fall of the republic at the end of the 18th century.

Despite this colossal extravagance and the enormously high-profile guest list he was able to attract, Beistegui did not generally warm to people, nor they to him.