Francois Mansart 1598-1666 is the French architect credited with introducing classicism during the Baroque period of architecture in France. He was a major proponent and innovator of a new classical development in the 17th Century. One of his famous signature inventions, which became known as the Mansard roof, can be seen on palaces and chateaux across Europe. It became synonymous with defining the architectural style of the Bourbon kings of France. The Mansard roof’s basic characteristics are its two slopes on all four sides, with the lower slope nearly vertical and the upper nearly horizontal. From the bottom line to the midpoint of the steep slopes, he incorporated gable windows, normally oval shaped, and slender ornate chimney stacks, which gave palaces a new and distinctive style.

King Louis XIII overthrew all the little papal kingdoms in France and became an absolute ruler with the most powerful army in Europe. Thus, there was no longer a need for medieval fortified castles and moats. This new freedom created a radical change in the lifestyles of the French nobility, who could now live in chateaux and palaces surrounded by fountains and gardens instead of axillaries and fortified walls. Mansart saw this need for a modern movement in architecture and to break away from the archaic Gothic style. He is considered one of the most accomplished of 17th-Century French architects; his work is known for its degree of classical balance and elegance. His contributions to French style and taste were continued by his great-grandnephew Jules Mansart ( born 1646 ) who served as Louis XIV’s chief architect. Together they created some of the most important and historic buildings in France during the 17th and 18th centuries.

François was born to a master carpenter. He was not trained as an architect but as a mason and a sculptor. He is thought to have learned his architectural skills in the studio of Salomon de Brose, the most popular architect of Henry IV's reign. Mansart was well known by the 1620s for his technique and classical approach as a draftsman, but he was seen as an obstinate and demanding perfectionist. Only an aristocrat like the chancellor to Gaston d'Orleans could afford to commission him since production costs were so high due to his attention to every detail. In 1626 Mansart redesigned and rebuilt the chateau of Balleroy. The duke was so proud of the results that he invited Mansart to renovate his other chateaux. With obsessive attention to every design element, Mansart’s construction designs ingeniously used a classical plan. This remarkable castle of the purest Louis XIII style was the property of the family of Balleroy until 1970, when the famous American editor Malcolm Forbes acquired it and created the world’s first Air Balloon museum on the property.

He was the director and architect of all the new royal additions at Versailles in 1710 including the north and south wings, the Royal Chapel on which he collaborated with Robert de Cotte, and the celebrated Hall of Mirrors decorated by Charles Le Brun. Outside the chateau proper he built the Grand Trianon and the Orangerie, as well as additional royal apartments not far away.

His best-known works in Paris are the Pont Royal, the great domed royal chapel Eglise du Dome dedicated to Saint Louis at Les Invalides (designed in 1680), the Place des Victoires (1684-86) followed by the Place Vendôme (1690). These works still set their imprint on the character of Paris. His position in France put him in place to create many historical monuments designed in a late Baroque architectural style influenced by Islamic Mosques in Turkey. He became one of the most important European architects of the 17th century.

In his later years Jules created his masterpiece the château of Dampiere-en-Yvelines. The masterly design commissioned by the Duc de Chevreuse ingeniously revived his great-uncle's famous mansard roof which he modeled and executed to perfection. The paved and gravel forecourt known as cour d'honneur is protected behind finely fashioned iron double gates. Its spaces are enclosed by the main block and its outbuildings known as corps de logis, and connected by symmetrically arranged balustrades, with a modest pediment entrance bordered by two projecting pavilions. Behind, the central axis is an extended formal garden and fountains laid out by André Le Nôtre. Jules’ sumptuous interiors of the chateau are perfectly intact, making it one of France’s most important architectural marvels.