Drôme is the southernmost department in the Auvergne-Rhône-Alpes region of Southeastern France. Named after the river Drôme, it had a population of 516,762 as of 2019. Drôme's prefecture is Valence. Saint-Vallier in Drôme was the birthplace of one of France's most famous courtesans, the noble-born Diane de Poitiers, long-term mistress of King Henri II.