The royal Château de Chambord at Chambord, Loir-et-Cher, France, is one of the most recognizable châteaux in the World because of its very distinct French Renaissance architecture which blends traditional French medieval forms with classical Renaissance structures. The building, which was never completed, was constructed by King François I in part to be near to his mistress the Comtesse de Thoury, Claude Rohan, wife of Julien de Clermont, a member of a very important family of France, whose domaine, the château de Muides, was adjacent. Her arms figure in the carved decor of the château.
Chambord is the largest château in the Loire Valley; it was built to serve as a hunting lodge for François I, who maintained his royal residences at Château de Blois and Château d'Amboise. The original design of the Château de Chambord is attributed, though with several doubts, to Domenico da Cortona. Some authors claim that the French Renaissance architect Philibert Delorme had a considerable role in the château's design, and others have suggested that Leonardo da Vinci may have designed it.
Chambord was altered considerably during the twenty years of its construction, (1519–1547), during which it was overseen on-site by Pierre Nepveu. With the château nearing completion, François showed off his enormous symbol of wealth and power by hosting his old archnemesis, Emperor Charles V at Chambord. In 1792, some of the furnishings were sold and timber removed. For a time the building was left abandoned, though in the 19th century some attempts were made at restoration. During the Second World War art works from the collections of the Louvre Museum and Compiègne were moved to Château de Chambord. Now open to the public, in 2007 the château received 700,000 visitors.
Châteaux in the 16th-century departed from castle architecture; while they were off-shoots of castles, with features commonly associated with them, they did not have serious defences. Extensive gardens and water features, such as a moat, were common amongst châteaux from this period. Chambord is no exception to this pattern. The layout is reminiscent of a typical castle with a keep, corner towers, and defended by a moat. Built in Renaissance style, the internal layout is an early example of the French and Italian style of grouping rooms into self-contained suites, a departure from the medieval style of corridor rooms.
The massive château is composed of a central keep with four immense bastion towers at the corners. The keep also forms part of the front wall of a larger compound with two more large towers. Bases for a possible further two towers are found at the rear, but these were never developed, and remain the same height as the wall. The château features 440 rooms, 282 fireplaces, and 84 staircases. Four rectangular vaulted hallways on each floor form a cross-shape.
One of the architectural highlights is the spectacular double helix open staircase that is the centerpiece of the château. The two helices ascend the three floors without ever meeting, illuminated from above by a sort of light house at the highest point of the château. There are suggestions that Leonardo da Vinci may have designed the staircase, but this has not been confirmed. Writer John Evelyn said of the staircase "it is devised with four (sic) entries or ascents, which cross one another, so that though four persons meet, they never come in sight, but by small loopholes, till they land. It consists of 274 steps (as I remember), and is an extraordinary work, but of far greater expense than use or beauty."
The château also features 128 meters of façade, more than 800 sculpted columns and an elaborately decorated roof. When François I commissioned the construction of Chambord, he wanted it to look like the skyline of Constantinople. The château is surrounded by a 52.5‑km² (13,000‑acre) wooded park and game reserve maintained with red deer, enclosed by a 31‑kilometer (20‑mile) wall. The king's plan to divert the Loire to surround the château came about only in a novel; Amadis of Gaul, which François had translated. In the novel the château is referred to as the Palace of Firm Isle.
Who designed Château Chambord is a matter of controversy. The original design of the Château de Chambord is attributed, though with several doubts, to Domenico da Cortona, whose wooden model for the design survived long enough to be drawn by André Félibien in the 17th century. Some authors, though, claim that the French Renaissance architect Philibert Delorme had a considerable role in the Château's design. In 1913 Marcel Reymond suggested that Leonardo da Vinci, a guest of François at Clos Lucé near Amboise, was responsible for the original design, which reflects Leonardo's plans for a château at Romorantin for the King's mother, and his interests in central planning and double helical staircases; the discussion has not yet concluded.
Regardless of who designed the château, on 6 September 1519 François Pombriant was ordered to begin construction of Château Chambord. The work was interrupted by the Italian War of 1521–1526, and work was slowed by dwindling royal funds and difficulties in laying the structure's foundations. By 1524, the walls were barely above ground level. Building resumed in September 1526, at which point 1,800 workers were employed building the château. At the time of the death of King François I in 1547, the work had cost 444,070 livres.
The château was built to act as a hunting lodge for King François I, however the king spent barely seven weeks there in total, comprising short hunting visits. As the château had been constructed with the purpose of short stays, it was actually not practical to live there on a longer-term basis. The massive rooms, open windows and high ceilings meant heating was impractical. Similarly, as the château was not surrounded by a village or estate, there was no immediate source of food other than game. This meant that all food had to be brought with the group, typically numbering up to 2,000 people at a time.