BOURBON-L'ARCHAMBAULT, a town of France, in the department of the Allier, 19 miles W. of Moulins. It was anciently the capital of the dukes of Bourbon, from whom the late royal family of France, and the existing sovereigns of Spain, Naples, and Lucca, are descended. It is now much frequented on account of its mineral waters, which are found to be peculiarly efficacious in nervous and rheumatic diseases. In 1789 it changed its name for that of Burgos-les-Bains. It contains some remarkable specimens of Gothic and Byzantine architecture. Pop. 3017.