The Romans loved wine so much that they are thought to have drunk 180 million litres a year — the equivalent of a bottle of wine per citizen per day.
But until now it has been unclear what exactly they were quaffing.
Researchers at the universities of York and Copenhagen have analysed Roman grape seeds discovered at classical sites in France and found they were close relatives of the modern syrah and pinot noir varieties.
Pinot noir is one of the oldest wine varieties in the world, although the date of its arrival in France is unclear. Some ancient sources claimed the Romans brought it with them, while others said the invaders had discovered that Gallic tribes were making wine from wild native grapes.
Researchers did not find an identical genetic match with modern-day seeds, but found a close relationship between pinot-savagnin and syrah-mondeuse blanche families.
Dr Jazmín Ramos-Madrigal, a postdoctoral researcher from the University of Copenhagen, said: "Based on writings by the Roman author and naturalist Pliny the Elder, and others, we know the Romans had advanced knowledge of wine-making and designated specific names to different grape varieties, but it has, so far, been impossible to link their Latin names to modern varieties. Now [through] genetics [we] know exactly what the Romans were growing."
Researchers used the genetic database of modern grapevines to compare 28 archaeological seeds from French sites dating back to the Iron Age, Roman era and medieval period. The researchers are sure the seeds were used to grow wines because the grapes would have been small, thick-skinned and full of seeds. Identical seeds were also found at two Roman sites 600km apart and dating back 2000 years.
One archaeological grape seed excavated from a medieval site in Orléans in central France was genetically identical to the savagnin blanc variety still grown today, meaning the same vines have been grown for at least 900 years. This variety, often confused with sauvignon blanc, can still be found in the Jura region, where it is used for vin jaune, as well as in parts of Central Europe, where it often goes by the name traminer.
Dr Nathan Wales, from the University of York, said: "These results could shed new light on the value of some grape varieties."