French wine originated in the 6th century BC, with the colonization of Southern Gaul by Greek settlers. Viticulture soon flourished with the founding of the Greek colony of Marseille. Wine has been around for thousands of years in the countries surrounding the Mediterranean, but France has made it a part of their civilization and has considered wine-making as an art for over two thousand years. Not only did the Gauls know how to cultivate the vine, they also knew how to prune it. Pruning creates an important distinction in the difference between wild vines and wine producing grapes. Before long, the wines produced in Gaul were exceptionally famous all around the world. The Roman Empire licensed regions in the south to produce wines. St. Martin of Tours was actively engaged in both spreading Christianity and planting vineyards. During the Middle Ages, monks maintained vineyards and conserved wine-making knowledge and skills. Monasteries had the resources, security, and motivation to produce a steady supply of wine both for celebrating mass and generating income. During this time, the best vineyards were owned by the monasteries and their wine was considered to be superior. Over time the nobility developed extensive vineyards. However, the French Revolution led to the confiscation of many of the vineyards owned by the Church and others. The advance of the French wine industry stopped abruptly as first Mildew and then Phylloxera spread throughout the country, indeed across all of Europe, leaving vineyards desolate. Then came an economic downturn in Europe followed by two world wars, and the French wine industry didn't fully recover for decades. Meanwhile, competition had arrived and threatened the treasured French "brands" such as Champagne and Bordeaux. This resulted in the establishment in 1935 of the Appellation d'origine contrôlée to protect French interests. Large investments, the economic upturn following World War II and a new generation of Vignerons yielded results in the 1970s and the following decades, creating the modern French wines we know today. French wine is produced all throughout France, in quantities between 50 and 60 million hectolitres per year, or 7–8 billion bottles. France is one of the largest wine producers in the world. French wine traces its history to the 6th century BC, with many of France's regions dating their wine-making history to Roman times. The wines produced range from expensive high-end wines sold internationally to more modest wines usually only seen within France such as the Margnat wines were during the post war period. France is the source of many grape varieties (Cabernet Sauvignon, Chardonnay, Pinot noir, Sauvignon blanc, Syrah) that are now planted throughout the world, as well as wine-making practices and styles of wine that have been adopted in other producing countries. Although some producers have benefited in recent years from rising prices and increased demand for some of the prestige wines from Burgundy and Bordeaux, the French wine industry as a whole has been influenced by a decline in domestic consumption, while internationally, it has had to compete with the increased success of many new world wines Two concepts central to higher end French wines are the notion of "terroir", which links the style of the wines to the specific locations where the grapes are grown and the wine is made, and the Appellation d'origine contrôlée (AOC) system, replaced by the Appellation d'Origin Protégée (AOP) system in 2012. Appellation rules closely define which grape varieties and winemaking practices are approved for classification in each of France's several hundred geographically defined appellations, which can cover entire regions, individual villages or even specific vineyards.