The road to Rome is a long one. Especially if you're starting from Kent. That's what Sigeric the Serious, a 10th-century Archbishop of Canterbury, did when he set off on foot to St Peter's in the Vatican to be consecrated by the pope. Luckily for the pilgrims who followed over the centuries, he made a note of his return journey, putting flesh on the bones of what was called the Via Francigena.
I was walking the final section of it – from Orvieto in Umbria to Rome – on a nine-day walking holiday launched last summer by Headwater. It takes hikers through some of the least touristy parts of Italy, past Etruscan settlements, volcanic lakes, majestic hilltop towns and blissfully empty landscapes of olive groves, oak forests and flower-filled meadows. The holiday doesn't stick slavishly to Sigeric's route and at times has to cheat a bit (you try walking into Rome on the motorways that have since sprung up), but it does make you wonder why the Via Francigena's popularity has waned while the pilgrims' route to Santiago de Compostela in northern Spain has soared.
Elegant, hilltop Orvieto was a delightful place to start the first 16km walk, even if it wasn't strictly on the Via Francigena. But within a couple of kilometres after descending from the town, I spotted the first red-and-white drawing of a man with a suitably medieval pageboy haircut, rucksack and staff. (Newer markers are daringly modern; they even include a female figure.)
Fields of gently waving wheat and bright-red poppies flanked quiet tracks, and a sheep farmer obligingly created a classic bucolic scene by bringing his flock into the road. At about the time I crossed an invisible border from Umbria into Lazio three hours later, I could see in the distance Lake Bolsena, the largest volcanic lake in Europe. I walked past tiny houses built into giant lava cliffs on the road to the attractive town of Bolsena, with its medieval quarter and black-sand beach. A jolting coffee at a beachfront café marked the end of my five-hour walk.
Serene views of the lake came with my dinner of buttery coregone freshwater fish at the Loriana Park Hotel, run by friendly sisters Antonella and Bianca. They gave me a substantial packed lunch for my next 16km stage to Montefiascone, a pretty medieval town on the edge of a volcanic crater. First I had a few climbs to reach a road overlooking the lake, where owners of large villas gave me serious garden envy with their enormous vegetable plots, vineyards and olive groves. As the path dipped in and out of woods, wild flowers were everywhere: tiny orchids, wild roses, broom, elderflower and yet more poppies. The scent was heavenly.
Lunch was in the dappled shade of the Parco di Turona nature reserve, home to some of the loveliest, lushest forest trails I've ever wandered through. The only sounds were those of the river Turona and a particularly happy cuckoo; the only movement came from scuttling lizards and zillions of butterflies swooping madly. Here I spotted the first concrete marker with the magic word "Roma" under a stencilled pilgrim, reminding me that this was an important route – even though I had yet to see another soul on it.
I emerged from the forest to tread on ancient history along the Roman road of Via Cassia. On the verge was the Quercia del Pellegrino, the Pilgrim's Oak, its cool shade compelling me to follow the example of countless pilgrims who had rested here.
The dull outskirts of Montefiascone were quickly forgotten after my uphill walk to the miniature pastel-coloured piazza in the old town. Just beyond the café tables, I could see the huge 17th-century dome of the town cathedral which, as I was to discover over the following days, is visible for miles around. From the Hotel Urbano V's rooftop terrace, I could see a wonderful vista: Lake Bolsena, the Apennine mountains and my next day's destination, Viterbo. It didn't look that far away, but it was 18km on foot. The hotel's delicious pappardelle al ragu and veal saltimbocca fortified me for the next stage.
The morning's joy of a descent rather than an ascent was enhanced by a strong sense of history I experienced along another stretch of the Via Cassia. As the path dodged under a railway and past meadows, I encountered my first – and only – fellow travellers: two Spaniards, two Danes and an Irish couple.
The Etruscan town of Viterbo looked uninviting on the approach, but its exquisite medieval quarter of San Pellegrino made up for it. My B&B, the 15th-century Terrazza Medioevale, was in the heart of it and run by the adorable mother and son Luciana and Daniele. The following day off from walking gave me time to explore Viterbo's cobbled alleys and stately palaces, as well as watch the vintage-car race Mille Miglia, which just happened to roar past my B&B's door.
The road out of Viterbo was the most dramatic I'd seen so far – high, almost overwhelming rock walls where the trees mingled at the top. Once the landscape calmed down a bit, it was back to tranquil wheat fields and olive groves. I was heading towards Vetralla, specifically the family-run Antica Locanda. At one point, the path veered cross-country, but the walking notes confidently led me to a peaceful picnic spot in an olive grove and eventually to the warm welcome of the Locanda and Patrizia's tasty wild-boar pasta.
At this stage, the holiday cheats a bit. My final day on the Via Francigena was a leisurely 14km walk through hazelnut groves and past abandoned medieval towers to Capranica, whose higgledy-piggledy old town was an unexpected delight. I was driven back to the Locanda by Patrizia's husband Bernardino, who took me to Rome the following day. You can find roads into Rome that aren't major routes, Bernardino told me, but it wouldn't be the Via Francigena. I recalled other approaches into towns, and how even more tedious the industrial outskirts of Rome would have been. I was content to be dropped off at the top of the Villa Borghese and walk two hours to the Vatican, where I picked up the final part of Sigeric the Serious's trail.
Sigeric's original walking notes are in the British Library, appropriately enough for a man whose nickname is thought to refer to his high level of learning. As I climbed the cupola of St Peter's and gazed over the rooftops of Rome, I was grateful to those scholars whose research turned Sigerac's jottings into a serious walk.
The writer travelled with Headwater (01606 720199; headwater.com) on the nine-day independent Orvieto to Rome walk, which starts at £1,299 per person. This includes British Airways flights from London to Rome, rail transfers, eight nights' B&B accommodation, six lunches, four evening meals, luggage transfers between hotels, walking notes and maps.