The sporadic fighting between the kings of England and France known as the Hundred Years War (1337–1453) changed both the political map of Europe and the nature and volume of the medieval wine trade. Both crowns claimed ownership of the wine regions of western France, which, through the wealthy port of bordeaux, supplied England with almost all her wine.
The hostilities had a marked effect on the wine trade. First the large and commercially successful vineyards of the haut pays, or ‘high country’, upstream from Bordeaux (gaillac, bergerac, buzet, cahors) were for the most part under French control. This increased English reliance on the lesser vineyards of Bordeaux and its environs, encouraging their expansion.