Paul-Henri-Benjamin d'Estournelles de Constant

Paul-Henri-Benjamin Balluet d'Estournelles de Constant was born at the Château de Clermont-Créans in Sarthe into an illustrious aristocratic family; his great-uncle was the famed Swiss-French author and political philosopher Benjamin Constant. Entering the French diplomatic service in 1876, Estournelles served in Montenegro, the Ottoman Empire, the Netherlands, and Tunisia, before being posted as Chargé d'Affaires in London in 1890, where he successfully defused the 1893 Siamese crisis that had brought Britain and France to the brink of war.

Concluding that diplomacy conducted behind closed doors bred distrust and war, Estournelles resigned from the foreign service in 1895, won election to the Chamber of Deputies, and in 1904 was elected to the French Senate representing Sarthe. At the First Hague Peace Conference in 1899, working alongside Léon Bourgeois, Estournelles was the primary diplomatic force behind the creation of the Permanent Court of Arbitration (PCA) in The Hague.

In 1902, Estournelles traveled to Washington, D.C., successfully convincing President Theodore Roosevelt to submit the long-standing US-Mexico Pious Fund dispute to the PCA, thereby providing the fledgling international tribunal with its very first operational case. In 1905, he founded the Association pour la conciliation internationale, dedicating his personal fortune to organizing Franco-German and Franco-British parliamentary exchange visits. In 1909, Estournelles was awarded the Nobel Peace Prize jointly with Belgian statesman Auguste Beernaert.