London, May 20 : Whenever someone talks about Facebook, Bebo and MySpace, it always flashes in our mind that such Internet sites are the creations of the modern world. However, a team of French researchers has challenged this idea by trawling through medieval documents to create the oldest detailed social network ever constructed.
Working from records of land transactions dating back as far as 1260, computer scientists have reconstructed the social ties that bound 10 villages in the province of Lot in southwest France.
The result is a rare look at how medieval peasants and lords were connected.
Documents showing medieval landholdings have been preserved in other parts of Europe, but are relatively rare in France, says one of the research team, Nathalie Villa of the University of Toulouse.
"In France, most of these types of documents disappeared during the revolution," Nature quoted Villa, as saying.
"There is little documentation of how peasants lived their lives," she added.
But in Lot, records of thousands of land transactions survived intact. Villa and her colleagues examined roughly 1,000 contracts, deeds and other documents stored in an online database, and analyzed the social ties between the people featured in them.
Two peasants whose names appeared on the same land contract, or who shared the same feudal lord, for example, would be considered to be linked in the social network - rather like Facebook 'friends' of today.
Some of the results were unsurprising.
Neighbours tended to be connected to one another, as did those who lived in the same generations. Generally, lowly serfs didn't get out much, whereas their lords were among the best-connected members of society.
But other findings proved more unexpected, Villa says.
For example, some well-connected peasants had a surprising number of social links beyond their village. And analysis of later documents also shows that the network may have changed substantially over the course of the Hundred Years' War - a prolonged conflict that smouldered on and off from 1337 to 1453, as two prominent families vied for the French throne.
Notably, one high-profile land-owning family, named Combelcau, all but disappeared after the War, says Villa. The team's results are reported in the journal Neurocomputing 1.
"It's a very impressive piece of work," says Paul Ormerod, an economist and historian with Volterra Consulting in London, who has modelled the social spread of medieval heresy against the Catholic Church.
Ormerod thinks that Villa's work represents the oldest network to date. "It shows that you can do serious quantitative networks with history," he says.
But Ormerod adds the network doesn't yet say much about medieval life.
He believes the work could be built on to show how medieval societies operated or changed over time.