sentences:  During the 13th century, the Graves was the principal wine region of Bordeaux.While there were some vines growing in the Entre-Deux-Mers, Saint-Émilion and Blaye, the Médoc during this period was virtually a barren marshland.At the turn of the 14th century, the town of Libourne was vying for dominance in the area, exporting 11,000 tons of wine to London from the 1308 vintage.