one of the great Renaissance architects of the 16th century and, possibly, the first French architect to possess some measure of the universal outlook of the Italian masters but without merely imitating them. Mindful that French architectural requirements differed from Italian, and respectful of native materials, he founded his designs on sound engineering principles. He assimilated the orders of classical architecture and mastered their use; but, being a man with an independent, logical turn of mind and a vigorous personality, he fused the orders with a delicacy of invention, restraint, and harmony characteristic of purest French classicism.

Delorme, the son of a master stonemason, lived at Rome (c. 1533–36), where he excavated and studied classical antiquities. It was very likely through a compatriot whom he met there, Cardinal Jean du Bellay, that he cultivated his broad and ardent humanist outlook. While building a château at Saint-Maur-des-Fossés for Cardinal du Bellay (c. 1541–47), he was appointed architect to the dauphin (who became Henry II in 1547 and named him abbé of Ivry in 1549). For Henry's mistress Diane de Poitiers, he designed the magnificent château at Anet (1547–56) and a bridge for the château of Chenonceaux (1556–59). Appointed overseer of buildings (1548), he created a number of important works, including the tomb of King Francis I at Saint-Denis (1547), additions to the palace of Fontainebleau (1548–58), and the new château at Saint-Germain-en-Laye. Unfortunately, most of his buildings have been destroyed and are known only from engravings.

Following Henry's death (1559), Delorme fell from royal favour and turned to writing Nouvelles Inventions pour bien bastir et à petits fraiz (1561) and Le Premier Tome de l'architecture de Philibert de L'Orme (1567, revised 1568), two architectural treatises expounding the theories behind his practices. These works also attest to the way in which Delorme successfully grafted the spirit of Renaissance new learning onto the classic French tradition. In 1564 the queen mother, Catherine de Médicis, recalled him to begin his last major work, the palace of the Tuileries, Paris.