Blois, a city of France, capital of the department of Loir-et-Cher, on the right bank of the Loire, and on the railway from Paris to Nantes, 100 m. S. W. of Paris; pop. in 1866,20,080. It is built on the declivity of a hill overlooking the river. The streets in the upper part are narrow and crooked, and some of them are too steep for the use of carriages, stairs being cut in several places for the accommodation of pedestrians. Blois contains many objects of interest, including a Gothic cathedral, the episcopal palace, the town house, and the ancient castle of the counts of Blois. It was early a place of importance, and during the middle ages was governed by counts descended from Hugh Capet, who also possessed the city of Chartres. The last of them, Guy II., sold his feudal estate to Louis of Orleans, brother of Charles VI., whose grandson, Louis XII., united it to the crown. The castle became a favorite resort of the princes of the house of Valois, and was enlarged and improved at various times until it was one of the handsomest palaces of the country.

Francis I., Henry II., Charles IX., and Henry III. held their courts in it, and the states general of France were twice convened there during the reign of Henry III.: in 1576, when they repealed the edict of pacification, and the king, unable to oppose the league, declared himself its chief; and in 1588, when the same prince, fearing he might be deprived of his crown and perhaps his life through the intrigues of the Lorraine princes, had the duke of Guise murdered by his body guards in the antechamber of his own apartments, and the cardinal of Lorraine secretly despatched, a few few hours later, in a more secluded room. When Maria de' Medici was in 1617 exiled from the court, she resided, virtually as a prisoner, in this castle, whence 18 months later she escaped through a high window. In 1814, on the approach of the allied armies to Paris, the empress Maria Louisa and the council of regency repaired for a while to this place. Afterward the castle was entirely neglected, and used as barracks for cavalry. During the later years of Louis Philippe's reiirn it was carefully restored. Blois has several literary and scientific societies, a botanical garden founded by Henry IV., a public library, a departmental college, and a diocesan seminary, besides hospitals and other public institutions.

It trades in wines, spirits, vinegar, staves, and licorice, and produces serges, hosiery, gloves, cutlery, and hardware. A handsome bridge of 11 arches, built in 1717, connects the town with the suburb of St. Gervais. The city is furnished with spring water through an old aqueduct believed to be of Roman origin.