History of Portuguese wine country unfavorable for viticulture, making the country a ready market for imported wines; its proximity to France, made French wines a natural source. At times the supply was threatened by political and military conflicts between the English and French crowns. New sources had to be found such as the wines of Portugal. Documents exist detailing Portuguese wine shipments from the Minho region to England occurring as early as the 12th century. These wines, including those from the wet northern region of modern-day Vinho Verde, were often light and astringent with noticeable acidity. Despite the new source, the variety of French
Madeira wine up large (112 gal/423 l) casks of wine known as "pipes" for their voyages to India. The intense heat in the holds of the ships had a transforming effect on the wine, as discovered by Madeira producers when one shipment was returned to the island after a long trip. The customer was found to prefer the taste of this style of wine, and Madeira labeled as "vinho da roda" (wines that have made a round trip) became very popular. Madeira producers found that aging the wine on long sea voyages was very costly, so began to develop methods on the