The Via Francigena (the Iter Francorum, or the "Frankish Route") is a branch of the Pilgrimage trail that goes between Canterbury and Rome, coming into full use starting around the 11th century.
Bishop Sigeric of Canterbury first made the journey to Rome in 990 AD to receive honors from the Pope. He kept details of his travels in a book, with pictures and maps of the route, which became the pilgrimage route of today, more or less.
The route contains lots of interesting cities, from the Roman stronghold of Aosta, with some great ruins to visit, to Ivrea, known for its orange-throwing carnevale, Vercelli for its rice (and the frogs who have a symbiotic relationship with it), Luni, for which the Lunigiana gets its name (there are over 160 castle and castle ruins to visit) and other compelling destinations like San Gimigiano and its towers and Siena with its Palio. It's a great route to trek today.
It's also a great route to take by car or train. The sudden influx of travelers in groups made travel, and subsequently trade, safer along these routes. Thus, the richest and most diverse cities with compelling 11th and 12th century architecture exist along the route.
If you'd like to walk the Italian sections of the Via, see below for the Lightfoot guides, which offer a wealth of information on trails and lodging long the route.
Some of the destinations on the Via Francigena trail of Northern Italy have information you can find by clicking or tapping on most of the town names on the map.
Via Francigena Map
Via Francigena Resource Guide
Via Francigena - Associazione Europea: Mostly in Italian, but you can download maps of the stages of the walk.
Association Via Francigena: Information site in English.
Confraternity of Pilgrims to Rome: Practical help and information for those making a pilgrimage to Rome by foot, bicycle or horse.
The Via Francigena - A site in English about the Via.
Notes on Walking the Francigena - Interested in how long it takes to go from Aosta to Rome. Here are some notes from a pilgrimage.
EuroVia - A site for pilgrims to share experiences.
Le Vie Francigene del Sud - Maps and resources for the Via Francigena south of Rome to Brindisi and other east coast ports.
FrancigenaLibrari - New Italian Government portal for Via Francigena information.
Recommended Books and Guides
LightFoot Guide to the via Francigena - Summit of the Great St Bernard Pass to St Peter's, Rome - Latest Maps and field notes on all aspects of walking the via Francigena in Italy, from the Great St. Bernard Pass to Rome. Lots of pictures and information on what you'll see along the way. Interesting even for those who don't choose to walk the via. You can also buy just the Italian section of the pilgrimage: LightFoot Guide to the via Francigena Edition 4 (Black and White) - Vercelli to St Peter's Square, Rome.
An Italian Odyssey: One Couple's Culinary and Cultural Pilgrimage - Find out what it's like when food lovers hit the Via Francigena. Read our review of An Italian Odyssey.