From about 1530, Francis I imported numerous Italian artists, such as Rosso Fiorentino (Giovanni Battista di Jacopo Rosso), Francesco Primaticcio, Sebastiano Serlio, Giacomo da Vignola, and Benvenuto Cellini. Most of these artists were followers of Michelangelo or Raphael, so that the new period of French architecture partook of Italian Mannerism. The style that resulted lasted until about 1590 and is sometimes known as the style of Henry II, although it actually was produced under five different kings, beginning late in the reign of Francis I.

The full influence of the new Italian style can best be seen in the château at Fontainebleau. In 1528 Francis I began to make revisions and additions to this medieval château, the exterior architecture being carried out by French builders under Gilles Le Breton. The Italian painter Rosso Fiorentino was placed in charge of the interior decoration of the Gallery of Francis I (c. 1533–45). The gallery is a long, narrow room covered by a wooden ceiling. On each side of the room is a high dado (i.e., the lower section of a wall) of carved walnut with rich decoration above of stucco relief sculpture and painting. As Rosso was a Mannerist painter, prominent French commissions went directly from the early Renaissance style of the Loire châteaus to Mannerism. Rosso, who died in 1540, was succeeded by another Italian, Primaticcio, who decorated the ballroom, or gallery (1548–56), of Henry II and added the wing called the Aile de la Belle Cheminée (1568).

The most important Italian architect to build in France was Serlio, who arrived in 1541 to take Rosso’s place as court architect. Serlio prepared plans for the rebuilding of the royal palace of the Louvre at Paris, but his ideas seem to have been too grandiose for Francis I. He did manage to build two châteaus, the casino of the Cardinal of Ferrara at Fontainebleau (1544–46), now destroyed, and the château of Ancy-le-Franc (begun 1546) in Burgundy. Serlio devoted most of his time to an architectural treatise that he had begun in Italy. Various books of the treatise were published during his lifetime from 1537 on, but the collected work was published after his death with the title Tutte l’opere d’architettura, et prospetiva (1619; “Complete Works of Architecture and Perspective”). It was influential in spreading the Renaissance style in France, England, and the Low Countries.

The influx of Italian artists soon compelled the French architects to adopt Renaissance principles of design as well as Renaissance ornamental details. Many French architects began to study the theory of design and often went to Italy as the source of the Renaissance style.

After Serlio’s failure with the palace of the Louvre in Paris, a French gentleman of the court, Pierre Lescot, was ordered to design and build a Renaissance palace to replace the medieval castle. Lescot, in collaboration with the sculptor Jean Goujon, designed a palace set around a square court about 175 feet (53 metres) wide. Only two sides, the west and south, of Lescot’s court were built (1546–51). The execution and amplification of this design extended to the middle of the 19th century. The small section carried out under Lescot, the Gallery of Francis I, reveals a thorough understanding of the principles of Italian design but is expressed in French terms. The Classical elements are used as low-relief surface decoration with little emphasis on mass.

The two leading French architects of the second half of the 16th century, Philibert Delorme and Jean Bullant, studied in Rome. Delorme was trained as a builder before going to Rome and, therefore, was always interested in the constructive side of architecture as well as in the theory of design. About 1547 Delorme was commissioned by the mistress of Henry II, Diane de Poitiers, to design her château at Anet. The original château (about 1547–52) formed three sides of a court closed at the front by a screen wall and entrance gateway. Much of the château has been destroyed; only the left wing of the house, the screen wall, and the chapel that formed part of the right wing survive. The entrance gateway, which originally contained Cellini’s bronze relief of Diana (now in the Louvre), is very Mannerist with a complicated superstructure, a semicircular arch with raised bands cutting across the moldings, and, at the top, a bronze group of a stag that strikes the hour with its hoof as the accompanying hounds bay mechanically. The chapel at Anet has a centralized Greek cross plan with a large circle capped by a dome at the crossing. The exterior of the chapel is Mannerist, with the windows cutting through the entablature and half pediments abutting the main block. Delorme commenced in 1564 a large palace called the Tuileries, since it was situated on the site of tileworks in front of the Louvre. Again, elements of Mannerism were visible. On the first story Delorme used his own so-called French order, consisting of Ionic half columns and pilasters with decorative bands across the shafts, but this order was actually an Italian Mannerist treatment of the Classical order.

Bullant’s architecture was rather like that of Vignola in that it was very Classical in details but often Mannerist in relationships. His early and best-preserved works were for Anne, duc de Montmorency and constable of France: part of the Château d’Ecouen (about 1555) and the chatelet (about 1560) at the Château de Chantilly. The architect Jacques Androuet du Cerceau the Elder prepared Les plus excellents bastiments de France (1576–79), a two-volume set of engravings that depict the new Renaissance 16th-century buildings of France, many of which have been destroyed or drastically altered. The Mannerist style died out in the early 17th century as slight hints of the Baroque style blended with a renewed classicism to gradually form the Academic style prevalent in the 17th century.