Albret (älbrā´), former duchy, SW France, in the Landes of Gascony. The powerful lords of Albret became kings of Navarre by the marriage (1484) of Jean d'Albret with Catherine de Foix, queen of Navarre, who also brought him Foix and Béarn. Their son, Henri d'Albret, married (1527) Margaret of Angoulême (Margaret of Navarre). The marriage added Armagnac to Henri's territories, which now included nearly all of Gascony. In 1550, Albret was raised to a duchy. Henri's daughter and heir, Jeanne d'Albret, married Antoine de Bourbon, and their combined territories were inherited by Henry of Navarre, who in 1589 became king of France as Henry IV. Henry added Albret to the royal domain in 1607 as part of the province of Gascony.