Built overlooking the River Seine by Thomas Gobert in the parkland surrounding the Château de Saint-Cloud, the building was inaugurated by Louis XIV in 1672 and first known as the Trianon de Saint-Cloud. The Trianon was renamed as the Pavillon du Mail in 1743 after being slightly modified. In 1785 the whole of the château estate, including the pavillon, was acquired by Marie Antoinette, the queen of the last king of France, Louis XVI. For his part in arranging the acquisition of the pavillon, the queen granted Louis Auguste Le Tonnelier de Breteuil the use of the estate, and he made the pavillon his official residence, and it was renamed to the Pavillon de Breteuil. During the French Revolution, Breteuil fled from France, and the state took ownership of the pavillon. Following the revolution, the pavillon was renovated by Napoleon, renamed as the Pavillon d'Italie. Until the fall of Napoleon in 1815, it was used as accommodation for visiting royalty. Following another restoration started in 1817, the pavillon, now the Pavillon de Breteuil again, was used as the official residence of a series of officials and dignitaries up until the start of the Franco-Prussian War. In 1870, as a result of shelling during that war, the château was destroyed and the pavillon was badly damaged.
Current usage
In 1875, the Diplomatic Conference of the Metre in Paris, which had been convened by the French government to try to reach an agreement on international collaboration for the maintenance and development of the metric system, established the International Committee for Weights and Measures to start preliminary work on the formulation of international standards. To facilitate their work, the French government offered them the use of a site in the Domaine de Saint-Cloud, which included the badly war-damaged Pavillon de Breteuil, which they accepted. Following an agreement signed on 25 April 1969 between the CIPM and the French government, functional privileges and immunities were granted to the BIPM as an international organistaion operating on the site of the Pavillon de Breteuil. It is the home of the International Prototype of the Kilogram, which lost its status as a standard on 20 May 2019. Since 1900, the building has been listed as part of the Domaine national de Saint-Cloud as an historic monument in France.
