The pilgrimage draws people from all over the world. There's a reason they keep coming back

This Pentecost Sunday, I found myself sitting on the dry grass of a field, turning my socks inside out for freshness, amid nine and a half thousand Catholics awaiting the celebration of Mass outdoors. It was about half past twelve, and we had been walking since half past seven. We were all pilgrims, en route from Notre Dame Cathedral in Paris to Notre Dame Cathedral in Chartres.

Over SaturdaySunday and Monday morning we were to travel roughly 70 miles, entirely on foot. My girlfriend had invited her sister and me, but hadn’t told us the details beyond what to pack. I went expecting something like a mobile retreat. Retreats I have been on have always been reflective, but also, typically, relaxing. But that distance, in that time, was penance. Of course we prayed, and our chapter – a group of between twenty and fifty pilgrims, typically gathered from a parish, school or scout troop – had two priests, one to hear confessions and another to lead meditations. But apart from prayer, there was work, and pain. Offering it up – along with the gifts of the French sunshine, and the breeze rippling the wheat fields – made me more ready for the sacrament than I have ever been.

The route between Paris and Chartres is the first leg of the Way of St James. In itself, however, it has been a pilgrim’s path since the Merovingians, thanks to a well in Chartres into which martyrs’ bodies were thrown. In the ninth century, Chartres Cathedral acquired a new relic: the Sancta Camisa, Mary’s veil or part of her shirt, which we know to be silk from first-century Palestine. Then 35 years ago, a young group decided to revive the route by gathering people together to make the pilgrimage annually at Pentecost, when a bank holiday weekend makes it more feasible for French pilgrims to complete the whole route.

They have since organised themselves into Notre Dame de Chrétienté, the charity which organises the pilgrimage with military efficiency. The pilgrimage now draws chapters not only from every region of France, but from all over the world. We had three chapters from England, and it was not so surprising when, one morning, I bumped into an American acquaintance I had met in Indiana last year. Mass at Chartres was preceded by a parade of the flags and banners of each chapter down the nave, then around and behind the altar. It seemed endless: each one a symbol of dozens of acts of love, gathered to God from east to west.

Apart from the distance, an element of the pilgrimage of which I had not been forewarned was its association with parishes, orders and organisations sometimes called the “traditionalist movement”. All the Masses were in the Extraordinary Form, and I hadn’t been to one since my undergraduate days. My girlfriend hadn’t thought the connection needed mentioning: where she grew up in France, this was an unremarkable part of Catholic practice.

But it was remarkable to me. There is no other event like this besides World Youth Day, which is top-down, as opposed to a spontaneous lay initiative. I wondered whether it might not be a mere coincidence that it was the work of “traditionalists”. Penance is what pilgrimage is really about. The Extraordinary Form has a longer Penitential Act. The language of its Offertory begs for mercy and expresses sorrow for sin, in addition to the admiration of God’s goodness expressed in the Ordinary Form’s. Depending on your metric, there’s three times as much breast-striking; and the Prayer of Humble Access is twice repeated.

So there’s a safely contained explanation for why “trads”, and not charismatic, “folk Mass”, or “mainstream” Catholics, would be the ones behind an international lay initiative like this. Perhaps those who feel more in need of penance are drawn to the Extraordinary Form, or perhaps it impresses the need for penance on those drawn to it for other reasons. Either way, pilgrimage would be a natural consequence.

But to generalise a little more boldly, it might have to do with wider trends which sociologists of religion know well. Faith flourishes when it is demanding, and when its sacred objects and materials are set apart from the mundane and profane. Beauty sets apart. Obedience to inherited forms, over which we intend no control, sets apart.

I tried to consider what an analogous event might be for a committed “Spirit of Vatican II” Catholic. A sponsored walk for Cafod, perhaps? It’s an interesting contrast. Why shouldn’t a sponsored walk draw a column of the faithful that stretches further down the road than the eye can see? It’s not a rhetorical question. I can give to charity alone, sat at my laptop with my debit card; no strenuous act of faith is a natural part of “making a difference”. But penance, unlike “changing the world”, redeems; and the Church is redeemed all of us together. If I can’t get time off to go next year, I hope I will be with the column in prayer throughout those three days.