A 600-year-old pinot noir grape is found in a medieval Frenc

Another study co-author, Ludovic Orlando, pointed out that the Hundred Years' War between England and France finally wrapped up in the mid-1400s.

And the brief life of France's patron saint, Joan of Arc, was also in the 15th century.

"She could have eaten the same grapes as us," the paleogeneticist at the University of Toulouse told AFP.

The seed was found in a toilet in a 15th-century hospital in Valenciennes in northern France. At the time, toilets were sometimes used as rubbish bins, the researchers explained.

Hundred Years War

The study, which was published in the journal Nature Communications, involved sequencing the genome of 54 grape seeds dating from the Bronze Age - from around 2300 BC - to the Middle Ages.

It confirms that generations of winegrowers had been using what are today called "clonal propagation" techniques, such as preserving cuttings of particular grape varieties for 600 years, the researchers said.

Ancient texts had offered indications this was happening, "but outside of paleogenomics, it is very difficult to characterise this technique", said Bouby of the Institute of Evolutionary Science of Montpellier.

But the new research found evidence this technique was being used in many areas as far back as the Iron Age, around 625-500 BC.

Evolutionary Science of Montpellier

The oldest grapes analysed in the study were from wild vines in the French region of Nimes dated to around 2000 BC.

Domesticated vines then started to appear between 625 and 500BC in France's southern Var region.

This lines up with when colonising Greeks were believed to have introduced viticulture - cultivating grapevines - to France, after founding the city of Marseille.

Orlando said it was already known that wine was traded at the time by the Greeks and the Etruscans, because of wine jugs called amphora that lasted through the centuries.

France

But the DNA of the grape seeds, particularly those from the ancient Roman period, revealed long-distance exchanges of domesticated grape varieties from places including Spain, the Balkans, the Caucasus and the Middle East.

It also showed there was plenty of genetic mixing of domesticated grape varieties and local wild vines during the Roman period, particularly in northern France.

In the future, "it would be very interesting to work closely with historians who have access to texts describing certain winegrowing techniques" to find out more, Orlando said.

Pinot noir, which is often associated with France's Burgundy region, is the fourth most widely grown grape in the world, according to the study.

She could have eaten the same grapes as us.

Putting it in context

Taste is what consumers judge first; availability is what determines whether they get the chance to judge it at all.

At a glance

The brief life of France's patron saint, Joan of Arc, was also in the 15th century
"She could have eaten the same grapes as us," the paleogeneticist at the University of Toulouse told AFP
The seed was found in a toilet in a 15th-century hospital in Valenciennes in northern France
The study, which was published in the journal Nature Communications, involved sequencing the genome of 54 grape seeds dating from the Bronze Age - from around 2300 BC - to the Middle Ages
Ancient texts had offered indications this was happening, "but outside of paleogenomics, it is very difficult to characterise this technique", said Bouby of the Institute of Evolutionary Science of Montpellier

The numbers worth knowing

It confirms that generations of winegrowers had been using what are today called "clonal propagation" techniques, such as preserving cuttings of particular grape varieties for 600 years, the researchers said
The oldest grapes analysed in the study were from wild vines in the French region of Nimes dated to around 2000 BC

The questions it raises

What should you know about France?