Vendôme, town (1990 pop. 18,359), Loir-et-Cher dept., N central France, in Orléanais. It is a manufacturing town with food processing, computer, and metal and electrical industries. The town developed around the Abbey of the Trinity (11th cent.) and during the Middle Ages was the prosperous center of the county (duchy after 1515) of Vendôme. Henry IV inherited the duchy as part of the Bourbon lands, united it with the royal domain in 1589, and gave the title of the duke of Vendôme to his illegitimate son César in 1598. Among the numerous monuments are the ruins of a château built during the 12th, 14th, and 15th cent.