The Via Eurasia / Via Francigena through France begins at Calais, runs mainly south and crosses the Swiss border just after Pontarlier. It has 37 stages and is 780 km long. In France, although the GR145 forms the approximate line of the original route, the earlier parts may not be well marked, and there are alternative itineraries in use. From Haute Marne onwards, the route is better defined and completely marked. There is a topo-guide to the GR145, produced by the FFRP, the main waymarking authority. Cyclists are currently using a route known as the Via Francigena in France, although there is no definite itinerary, only a list of towns through which it passes. So far the Italian section is the only part completely defined and mapped as Eurovelo route no 5.
The first pilgrim route, the Lombard Way, ran though the Frankish kingdoms of Neustria and Burgundy before entering Lombard territory. After 774, it became known as the Via Francigena. During the Middle Ages, the Frankish kingdoms became united and centred on Paris, where French kings were crowned and buried.
Unlike England, France remained a Catholic country with direct allegiance to the Pope in Rome. Pilgrimage was promoted in 1300, when Pope Boniface VIII declared a Jubilee year, with complete forgiveness of sins for pilgrims to Rome. Jubilee years were declared every 25 or 50 years thereafter, until the Reformation.
The Via Francigena was not a single road, like a Roman road, paved with stone blocks and with stables provided at intervals, where official travellers could change horses. Rather, it comprised several possible routes that changed over the centuries as trade and pilgrimage waxed and waned. Depending on the time of year, the political situation, and the relative popularity of the shrines of the saints situated along the route, travellers may have used any of three or four crossings of the Alps and the Apennines. Unlike the Roman roads, the Via Francigena did not connect cities, but relied more on abbeys to accommodate travellers.
Web sites for information and maps:
The Routes du Terroir site gives an overview of the route from the point of view of gastronomy, motoring and general tourism. Laviafrancigenaenfrance.fr
The CVF (Camminando sulla via Francigena)
The alternative organization Association Internationale Via Francigena Francigena-international.org has a website with its own resources.