Once a much larger estate, it was owned by King Leopold II of Belgium (1835 – 1909), from whom the present villa derives its name. He gifted the estate to his mistress Blanche Zélia Joséphine Delacroix (1883 – 1948). The King was 65 when he met the 16-year-old Blanche in Paris, where she was allegedly working as a prostitute. She was probably the most prominent and notorious of Leopold's mistresses. She was very unpopular, possibly in the light of all the extravagant gifts that Leopold lavished upon her, including land, jewels and the noble title Baronne de Vaughan. When Leopold died, Blanche was evicted from the villa, and his nephew King Albert I became the new owner.

 

During World War I, the villa was used as a military hospital. And In 1919, French aristocrat Thérèse Vitali, Comtesse de Beauchamp, acquired the property and commissioned various modifications.

 

It was the American architect and interior decorator Ogden Codman, Jr. (1863 – 1951), who designed the stunning neo-Palladian villa that stands majestically on the site today. He purchased the dozen existing structures that comprised the property and set about creating his vision with its fantastic architecture, stunning vista, and lavishly landscaped gardens. The original architectural drawings, together with various letters and photographs of the newly completed property are in the collections of the Society for the Preservation of New England Antiquities, also known as "Historic New England," and headquartered in Boston, Massachusetts.

 

Codman began work in 1929, and it was completed two years later. However, possibly due to his demandingly high standards and lavish spending, he got into financial difficulties and could not afford to live there. He had to resort to renting it out to wealthy clients.

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The Duke and Duchess Of Windsor (formerly the British King Edward VIII and the American socialite Wallis Simpson) tried to lease the villa. However, they insisted that they would have to make many changes to the property which went against Codman's architectural aesthetic and strict protective clauses. Negotiations in a Paris Hotel broke down over the many restrictions imposed by Codman. He responded, "I regret that the House of Codman is unable to do business with the House of Windsor."

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When Codman died in 1951, the estate was sold to Canadian financier Izaak Walton Killam (1885-1955) whose wife Dorothy J. Killam inherited it following his death a few years later. In the late 1950s, Mrs. Killam sold the villa to Fiat president Gianni Agnelli (1921–2003) and wife Marella Agnelli. The Agnellis then sold the villa to Dorothy J. Killam in 1963, and she lived there until she died in 1965.