The story of the Hôtel de Rohan and the Hôtel de Soubise is the story of the mad ambition that drove the house of the Princes de Soubise in their dream of grandeur from 1705 to 1752. The prince's ambition was twofold: to transform the Hôtel de Guise into the Hôtel de Soubise for the crown prince, and to build a second hotel for his fifth son, the Prince-Bishop of Strasbourg. The two hotels face each other, separated by a beautiful garden in the historic heart of the city. As the various building campaigns progressed, nothing was too good for the Princes de Soubise. A paradoxical urban ensemble that bears witness both to the Parisian "courtyard-garden" model and to architects' inventiveness in adapting it to an irregular plot, and to the political role of buildings for the French aristocracy of the 18th century.