Building of the château was begun by Francis I in 1519, and was completed in 1547. Florentine artist Leonardo da Vinci paid a short visit to the building during its construction and added a few embellishments to it. The structure, containing 440 rooms,  365 fireplaces, 13 great staircases, and stables to accommodate 1,200 horses, stands in a park surrounded by a wall of 22 miles in circumference.  1,800 men worked on the chateau.

The design was actually simplified from the King's original plans for financial reasons... it is difficult to grasp how it would have looked had he unlimited funds to spend.  In fact, the King only spent about 8 nights at Chambord and most of the rooms were never furnished.

After Francis I's death in 1574 the castle was practically unused for about fifty years.

After having passed through other hands, the chateau risked being demolished after the Revolution and in 1793 the furnishings were dispersed. In 1947 the State began restorations which were continued for 30 years. 

The spiral staircase, which is in fact two separate staircases which rise opposite one another like DNA, is related to a project by Leonardo which consisted of four distinct superimposed flights of stairs, in order words, just as many stairs as quarters and arms of the cross of the castle. It is therefore likely that Leonardo da Vinci staircase, which may have been conceived for Chambord, was then simplified when it was built by the master masons of the building yard.  There are about 148 steps in each staircase, which is a continuous run with no landings.

Although the rumour goes that the King wanted the double staircase in order to visit his mistress without his wife's knowledge, in fact it this could not be the case, as the sides are open.

Some of the hundreds of varied structures on the roof

Another, smaller staircase in one of the courtyards.

A billiard table supposedly owned by King Charles II