Aquitaine, archaic Guyenne or Guienne, is a historical region of Southwestern France and a former administrative region. Since 1 January 2016 it has been part of the administrative region of Nouvelle-Aquitaine. It is situated in the southwest corner of metropolitan France, along the Atlantic Ocean and the Pyrenees mountain range on the border with …Aquitaine, archaic Guyenne or Guienne, is a historical region of Southwestern France and a former administrative region. Since 1 January 2016 it has been part of the administrative region of Nouvelle-Aquitaine. It is situated in the southwest corner of metropolitan France, along the Atlantic Ocean and the Pyrenees mountain range on the border with Spain; for most of its written history Bordeaux has been a vital port and administrative centre. It is composed of the five departments of Dordogne, Lot-et-Garonne, Pyrénées-Atlantiques, Landes and Gironde. Gallia Aquitania was established by the Romans in ancient times and in the Middle Ages, Aquitaine was a kingdom and a duchy, whose boundaries fluctuated considerably.