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.

Occitan, also known as lenga d'òc by its native speakers, sometimes also referred to as Provençal, is a Romance language spoken in Southern France, Monaco, Italy's Occitan Valleys, as well as Spain's Val d'Aran in Catalonia; collectively, these regions are sometimes referred to as Occitania. It is also spoken in Calabria in a linguistic enclave of Cosenza area. Some include Catalan in Occitan, as the distance between this language and some Occitan dialects is similar to the distance between different Occitan dialects. Catalan was considered a dialect of Occitan until the end of the 19th century and still today remains its closest relative.