The Romans loved wine so much that at the peak of empire it was estimated the capital was drinking 180 million litres annually, the equivalent of a bottle of wine per citizen per day.
Yet until now it has been unclear what exactly they were quaffing.
Now 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 its arrival in France has been unclear. Some ancient sources claimed the Romans brought it with them, while others said the invaders had discovered Gallic tribes were making wine from wild native grapes.
Although researchers did not find an identical genetic match with modern-day seeds, they 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 winemaking and designated specific names to different grape varieties, but it has so far been impossible to link their Latin names to modern varieties.
“Now we have the opportunity to use genetics to know exactly what the Romans were growing in their vineyards.”
Researchers used the extensive genetic database of modern grapevines to test and 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 they would have been small, thick-skinned and full of seeds which would not have been good for eating. Identical seeds were also found at two Roman sites separated by more than 372 miles (600km), and dating back 2,000 years ago.
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, which is often confused with Sauvignon Blanc, can still be found growing in the Jura region of France, where it is used to produce bottles of 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: “It is rather unconventional to trace an uninterrupted genetic lineage for hundreds of years into the past.
“For the wine industry today, these results could shed new light on the value of some grape varieties; even if we don’t see them in popular use in wines today, they were once highly valued by past wine lovers and so are perhaps worth a closer look.”
The researchers now hope to find more seeds which could reveal even more grape wine varieties.
The research was published in the journal Nature Plants.