Although vines had been cultivated from the wild Vitis vinifera grape for millennia, it wasn't until the Greek colonization that wine-making flourished. Viticulture was introduced into Sicily and southern Italy by the Mycenaean Greeks, and was well established when the extensive Greek colonization transpired around 800 BC. It was during the Roman defeat of the Carthaginians (acknowledged masters of wine-making) in the 2nd century BC that Italian wine production began to further flourish. Large-scale, slave-run plantations sprang up in many coastal areas and spread to such an extent that, in AD 92, emperor Domitian was forced to destroy a great number of vineyards in order to free up fertile land for food production.
During this time, viticulture outside of Italy was prohibited under Roman law. Exports to the provinces were reciprocated in exchange for more slaves, especially from Gaul where trade was intense, according to Pliny, due to the inhabitants being besotted with Italian wine, drinking it unmixed and without restraint. It was customary to mix wine with a good proportion of water which may otherwise have been unpalatable, making wine drinking a fundamental part of early Italian life.
As the laws on provincial viticulture were relaxed, vast vineyards began to flourish in the rest of Europe, especially Gaul (present day France) and Hispania. This coincided with the cultivation of new vines, like biturica (ancestor of the Cabernets). These vineyards became hugely successful, to the point that Italy ultimately became an import centre for provincial wines.
Depending on the vintage, modern Italy is the world's largest or second largest wine producer. In 2005, production was about 20% of the global total, second only to France, which produced 26%. In the same year, Italy's share in dollar value of table wine imports into the U.S. was 32%, Australia's was 24%, and France's was 20%. Along with Australia, Italy's market share has rapidly increased in recent years.
In 1963, the first official Italian system of classification of wines was launched. Since then, several modifications and additions to the legislation have been made (a major one in 1992), the last of which, in 2010, has established four basic categories, which are consistent with the last EU regulation in matter of wine (2008–09). The categories, from the bottom level to the top one, are:
Vini (Wines - informally called 'generic wines'): These are wines that can be produced anywhere in the territory of the EU; no indication of geographical origin, of the grape varieties used, or of the vintage is allowed on the label. (The label only reports the color of the wine.)
Vini Varietali (Varietal Wines): These are generic wines that are made either mostly (at least 85%) from one kind of authorized 'international' grapes (Cabernet Franc, Cabernet Sauvignon, Chardonnay, Merlot, Sauvignon blanc, Syrah) or entirely from two or more of them. The grape(s) and the vintage can be indicated on the label. (The prohibition to indicate the geographical origin is instead maintained. These wines can be produced anywhere in the territory of the EU.)
Vini IGP (Wines with Protected Geographical Indication): This category (also traditionally implemented in Italy as IGT - Typical Geographical Indication) is reserved to wines produced in a specific territory within Italy and following a series of specific and precise regulations on authorized varieties, viticultural and vinification practices, organoleptic and chemico-physical characteristics, labeling instructions, etc. Currently (2014) there exist 118 IGPs/IGTs.
Vini DOP (Wines with Protected Designation of Origin): This category includes two sub-categories, i.e. Vini DOC (Controlled Designation of Origin) and Vini DOCG (Controlled and Guaranteed Designation of Origin). DOC wines must have been IGP wines for at least 5 years. They generally come from smaller regions, within a certain IGP territory, that are particularly vocated for their climatic and geological characteristics and for the quality and originality of the local winemaking traditions. They also must follow stricter production regulations than IGP wines. A DOC wine can be promoted to DOCG if it has been a DOC for at least 10 years. In addition to fulfilling the requisites for DOC wines (since that's the category they come from), before commercialization DOCG wines must pass stricter analyses, including a tasting by a specifically appointed committee. DOCG wines have also demonstrated a superior commercial success. Currently (2014) there exist 332 DOCs and 73 DOCGs for a total of 405 DOPs.
A number of sub-categories also exist regulating the production of sparkling wines (e.g. Vino Spumante, Vino Spumante di Qualità, Vino Spumante di Qualità di Tipo Aromatico, Vino Frizzante).
Within the DOP category, 'Classico' is a wine produced in the historically oldest part of the protected territory. 'Superiore' is a wine with at least 0.5 more alc%/vol than its correspondent regular DOP wine and produced using a smaller allowed quantity of grapes per hectare, generally yielding a higher quality. 'Riserva' is a wine that has been aged for a minimum period of time, depending on the typology (red, white, Traditional-method sparkling, Charmat-method sparkling). Sometimes, 'Classico' or 'Superiore' are themselves part of the name of the DOP (e.g. Chianti Classico DOCG or Soave Superiore DOCG).
The Italian Ministry of Agriculture (MIPAAF) regularly publishes updates to the official classification.
It is important to remark that looser regulations do not necessarily correspond to lower quality. In fact, many IGP wines are actually top level products, mainly due to the special skills of their producers (e.g. so called "Super Tuscan" wines are generally IGP wines, but there are also several other IGP wines of superior quality).
Unlike France, Italy has never had an official classification of its best 'crus'. Private initiatives like the Comitato Grandi Cru d'Italia (Committee of the Grand Crus of Italy) and the Instituto del Vino Italiano di Qualità—Grandi marchi (Institute of Quality Italian Wine—Great Brands) each gather a selection of renowned top Italian wine producers, in an attempt to unofficially represent the Italian wine excellence.