A best-seller some years back told us “How the Irish Saved Civilization.”

Bit of a stretch, but there’s plenty of evidence that a lot of Western culture and more to the point Christian culture was preserved in the monasteries of Ireland where monks copied ancient texts and saved traditions and relics during the Dark Ages.

That’s what “Pilgrimage” is about; a remote monastery, filled with penitent men and boy apprentices, labor on the land and guard a holy relic from Vikings, Normans and other infidels in the 13th century.

Then a papal envoy arrives — “The Cistercian” (Paris-born actor Stanley Weber). “The Grey Foreigner” is arrogant and high-handed. Rome needs the relic. There’s a Crusade coming, and relics are good for recruiting. And he’s taking it.

“Rome has spoken…there is no debate.”

But just getting it out of Ireland will be a chore. “Infidels surround us…heretics.”

He’s not just talking about Irish pagans. Just a hundred years have passed since the Norman conquest of England, and they’re still galloping all over the Emerald Isle, divvying up land and rounding up Irish serfs.

So a small entourage is assigned to convoy the holy object, including the herbal healer Brother Ciaran (John Lynch), a brooding mute (Jon Bernthal) and a novice monk, Brother Diarmuid, played by Tom Holland (the new Spider-Man).

On their journey they will face superstitions, clan infighting and treachery and each will be severely tested. As “No one but the pure of heart can touch the relic and live,” you see where the boy Diarmuid comes in.

A Norman knight (Raymond Armitage) may help or hinder their quest. There are runes to be understood, a haunted forest to traverse and much blood will be spilled.

As an aficionado of films set in this superstitious, factional and dystopian corner of history, I appreciated the obscure Gaelic the Irish monks speak (in early scenes), the grim, grimy and short lives depicted and the way Jamie Hannigan’s script lets us see ways that superstitions held long ago can be explained through natural phenomena that we understand today.

Faith, of course, is another matter. If you believe a holy relic has great power, you may have your reasons.

Weber is perfectly oily as Brother Geraldus, the Cistercian, who has a flexibly expedient collection of beliefs, edicts, dogmas and myths that  he lives by — whatever gets this relic to Rome.

Holland is earnest enough as young Diarmuid, a boy who grows into himself as he grasps this mission. But it is Bernthal, playing a man who no longer speaks but who surely must have awful secrets he’s keeping, who captures us. The “Baby Driver,” “Sicario” and “Walking Dead” star has a ferocious screen presence, a menace we can sense even if he is standing stock still.

Bernthal’s mute is like Liam Neeson’s divorced dad in “Taken.” He’s got “particular skills.”  You just know it.

It’s not one of the great Middle Ages movies, not on a par with “The Name of the Rose,” “The Advocate,” “The Reckoning” or “The Secret of Kells.”

But this simple quest tale recreates a primitive era when Christians believed as Islamic terrorists believe today — that salvation and eternal life comes from self-sacrifice. And Bernthal’s resolute, fearsome and touching performance make this “Pilgrimage” well worth the journey.

MPAA Rating: unrated, with graphic violence

Cast: Tom Holland, Jon Bernthal, Richard Armitage, Stanley Webber, John Lynch

Credits: Directed by  Brendan Muldowney, script by Jamie Hannigan. An RLJ Entertainment release. 

Running time: 1:36