The Royal Château de Blois is located in the Loir-et-Cher département in the Loire Valley, in France. The residence of several French kings, it is also the place where Joan of Arc went in 1429 to be blessed by the Archbishop of Reims before departing with her army to drive the English from Orléans.
Built in the middle of the town that it effectively controlled, the château of Blois comprises several buildings constructed from the 13th to the 17th century around the main courtyard. Its most famous piece of architecture is the magnificent spiral staircase in the François I wing.
The medieval castle was purchased in 1391 by Louis, duc d’Orléans, brother of Charles VI; after the duke’s assassination, his widow, Valentine de Milan, retired to Blois. It was inherited by his son, Charles d’Orléans the poet, who was taken prisoner at Agincourt and spent twenty-five years as a hostage in England, before returning to his beloved Blois, which he partly rebuilt as a more commodious habitation. It became the favourite royal residence and the political capital of the kingdom under Charles’ son King Louis XII. At the beginning of the 1500s, the king initiated a reconstruction of the main block of the entry and the creation of an Italian garden in terraced parterres that occupied the present Place Victor Hugo and the site of the railway station. In 1890 the construction of the Avenue Victor Hugo destroyed the remainder of the gardens.
This wing, of red brick and grey stone, forms the main entrance to the château, and features a statue of the mounted king above the entrance. Although the style is principally Gothic, as the profiles of moldings, the lobed arches and the pinnacles attest, there are elements of Renaissance architecture present, such as a smaller chandelier.
The rear of the François I wing, facing over central Blois.
 François I
When François I took power, his wife Queen Claude had him refurbish Blois with the intention of moving to it from the Château d’Amboise. François initiated the construction of a brand-new wing and created one of the period’s most important libraries in the castle. But, after the death of his wife in 1524, he spent very little time at Blois and the massive library was moved to the royal Château de Fontainebleau where it was used to form the royal library that forms the core today of the Bibliothèque Nationale de France.
In this wing, the architecture and ornamentation are marked by Italian influence. At the centre is the monumental spiral staircase, covered with fine bas-relief sculptures and looking out onto the château’s central court. Behind this wing is the façade of the Loges, characterised by a series of disconnected niches.
 Henri III
King Henri III, driven from Paris during the French Wars of Religion, lived at Blois and held the Estates-General convention there in 1576 and 1588. It was during this convention that the king had his arch-enemy, the duc de Guise, assassinated by the king’s bodyguard known as "the Forty-five", when the duke came to the Chateau for a meeting with Henri. They also killed his brother Louis II, Cardinal of Guise the following day in the dungeons.
The Chambre du Roi with Henry IV’s H in the floor tiles
 Henri IV
After this, the castle was occupied by Henri IV, the 1st Bourbon monarch. On Henri’s death, it became the place of exile for his widow, Marie de Medici, when she was expelled from the court of her son, Louis XIII.
The Gaston d’Orléans wing, never completed.
 Gaston d’Orléans
In 1626, King Louis XIII gave the Château of Blois to his brother Gaston d’Orléans as a marriage gift. In 1635 there was another attempt to develop the castle but on Gaston’s death in 1660, it was abandoned. The task of developing this wing was given to François Mansart, a well-known architect of the time. This wing makes up the rear wall of the court, directly opposite the Louis XII wing. The central section is composed of three horizontal layers where the superposition of Doric, Ionic and Corinthian orders can be seen.
By the time of the French Revolution the immense castle had been neglected for more than one hundred and thirty years, and the revolutionaries, determined to wipe out any symbol of the old nobility while enriching themselves, ransacked the castle and stole many of its statues, royal emblems and coats of arms. In a state of near total disrepair it was scheduled to be demolished but was given a reprieve as a military barracks.
 Preservation as a monument
The "chambre de secrets", mistakenly believed to be Catherine de’ Medici’s secret hiding place for poisons.
In 1841, under the direction of King Louis-Philippe, the Château de Blois was classified as a historic monument. It was restored under the direction of the architect Felix Duban, to whom is due the painted decoration on walls and beamed ceilings. The château was turned into a museum. On view for visitors are the supposed poison cabinets of Catherine de’ Medici. Most likely this room, the "chamber of secrets," had a much more banal purpose: exhibiting precious objects for guests.
Today, the château is owned by the town of Blois and is a tourist attraction.