Amboise, a town of France, in the department of Indre-et-Loire, on the left bank of the Loire, 14 m. E. of Tours; pop. in 1866, 4,188. The town was rendered conspicuous at the opening of the French religious wars, in the 16th century, by the plot framed there against the Guises, known as the conspiracy of Am-boise. The ancient castle, which has been the residence of several kings of France, stands on a rocky precipice, and is almost inaccessible. It is of Roman origin, was rebuilt in the 4th century, and lastly renovated by Louis Philippe. Abd-el-Kader was confined here during the greater part of his captivity. The town has manufactures of firearms and files.