Tonight I’ve been poring through archaeological notes on the nature of ancient Celtic religion for another writing project. Sometimes research is tedious work, but tonight from the dry fragments of archaeological data, with the full moon peering in my window, a ghost rose up and took hold of me, and I want to share its tale. Tonight under this full moon, let me tell you a story.

We are in the soft green landscape of northern Gaul, its wooded hills and valleys crossed by many streams. We are in the territory of the Bellovaci, a strong Belgic tribe. Caesar’s legions have not yet come to conquer this land – it is a tribal dominion still. That moon pours light over the landscape, a wide stream that courses by the walls of the dunum, the fortified city standing on the slope overlooking the valley. Inside the walls, buildings cluster, thatched roofs over timber-framed and wattle walls. Just inside the entrance gate of the dunum, there is a space set apart from all the rest.

A tall wooden palisade guards the boundary of this space, enclosing it seven feet high with pole stakes but for an entrance gate facing us at the east. At intervals along these walls stand tall posts, towering over the palisade, and on each is hung a set of battered arms: sword, spear, and the man-sized oval shields of Gaulish tribes, painted with now-faded tribal devices, cut and spattered with the traces of battle. Here and there, a Roman helm and shield hang, or perhaps a Greek set. The captured trophies of rival tribes and nations. And over the eastern entrance in the palisade, a great wooden portal looms high above us. Its double gates are hung on thick timber uprights which support two ranks of heavy lintel beams, as thick as a man’s waist. We can see the ornate carvings on the beams and gate glinting in the shifting light. We recognize these carvings: sinuous and twisting, coursing spirals and geometries, the artful madness of La Tène Celtic design, brought to life by its colorful paint and the flickering torches to either side of the gate. In the shadowed spaces between the ranked beams of the portal over the gates, we can see rows of skulls: dead warriors set to watching the gateway between the outer world and the sanctuary within. The gates swing outward.

We cross a threshold between the uprights of the portal and step onto a narrow wooden footbridge which spans the eight feet of deep boundary ditch inside the palisade. To either side of the footbridge, in the ditch and up against the palisade wall, the skulls of horned cattle are stacked into mounds, all facing us as we move through the crossing. Apotropaic guardians like the dead warriors on the outer walls, their eye hollows watch us. Beyond the stacked cattle heads, we can see the ditch running along the circumference of the enclosure, and in it the layered remains of many offerings: countless animal bones; cattle, pigs, horses, sheep, layered in with thousands of rusted, broken swords, splintered shields, old spearheads, decaying leather scabbards and the detritus of endless bits of old weaponry. For hundreds of years these offerings have been laid down here, one atop another as the older sacrifices sink into the earth at the bottom of the boundary ditch. When the arms displayed on the walls rust and their leather strappings crumble enough to fall, they will be laid into the boundary ditch with the bones of the most recent sacrificial animals, and another set will take their place.

In the precise geometric center of the rectangular enclosure, a roofed structure stands, its four ornately carved and decorated corner posts carefully aligned to the cardinal directions. A temple. Within its shelter, the hollow altars are delved into the earth: nine circular pits cut deep into the soil in an open circle facing us as we approach from the east; and in the center of the circle, a tenth, larger oval pit. A heavy-hewn table stands before the structure, blood-stained, and nearby also are cooking-pits. Here the sacrifices are made to the poetic invocations of the Vates, the Druidic priests who are entrusted with sacrifices, divinations, and the rites of religious observance. We can almost hear their intonations, the words uplifted, the sonorous chantings in the ancient Gaulish tongue. Here the offerings are dedicated – the many bright treasures, the fine weapons, the poured libations. The animals are brought, their blood spilled; parts of their bodies are given to the Gods and offered in the pits of the hollow altars, entrances into the Otherworld. The rest of the meat, sanctified by the touch of the Gods, is brought out and cooked in the cooking-fires, and shared with the gathered people of the tribe. The hollow altars will be covered between ceremonies, and the portions of the animals given to the Gods within them will be left there until the bones are free of flesh, and then the bones will be brought out and placed in the boundary ditch, as the ritual cycle continues.

Outside the temple, another, smaller building is enclosed with walls, and within are heaped treasures upon treasures. Golden torcs, arm-bands, necklaces, anklets, belts. Cups and cauldrons in gold and some silver; hand-mirrors, chains, enameled, jeweled, twisting with ornate La Tène ornament. Wooden chests overflow with objects captured, created, offered. Treasures up on treasures, and more weapons – fine, heirloom weapons. Baskets of coin gleam on the floor, some so old that the basket-weavings are disintegrating and the treasures spill onto the earthen floor, where they are slowly sinking in to the soil under the weight of layers up on layers of offerings. Humbler offerings litter the floor, too: ceramic and earthenware cups, fragmented crockery, bronze and iron tools, objects too old to be recognizable. How deep have the layered offerings sunk into the earth inside this treasure-house? It is never guarded except by the spirits. No one would ever think of stealing gifts already belonging to the Otherworld.

And here is another, smaller structure in the corner of the enclosure, glinting white by the moon’s light. Nearing, we discern that it takes its whiteness from the bones of which it is built, and the gleaming weapons hung upon it. A little square shrine built all of bones it is. Carefully stacked for stability, human long-bones criss-crossed make up its lower tiers; here and there intermixed with the leg-bones of horses. On its outer faces are hung more shields and weapons, and its upper surfaces are protected by a layer of shoulder-blade bones. An opening faces us, again toward the east, and within we can discern a floor carefully tiled with iliac bones, surrounding a round posthole in which stands a wooden icon with unfathomable staring eyes, its base set into deep, soft layers of human ash within the posthole. It is not simply a shrine for the ancestors of the tribe – it is a shrine built of ancestors, the bones of the honored dead raised up into a structure for their reverence. How many ancestors stand here? How many generations?

One artist’s interpretation of a Gaulish sanctuary

In the remaining corner of the sanctuary enclosure, behind the sacrificial temple, there stands a copse of trees. A little piece of the forest that was cleared to build the dunum whose walls surround this sanctuary, this grove of trees was left untouched and simply enclosed by the boundary ditch and palisade. It is a home for the Gods within the sacred precinct of the sanctuary.

This is a Gaulish Celtic sanctuary as it might have looked while still in use, before the destruction of public Gaulish religion. I’ve combined elements of a few different sanctuaries for the sake of illustrating the different kinds of shrines that were in use, but almost everything I’ve described here is based on archaeological records, with just a few bits filled in from contemporary texts. These sanctuaries were in continuous use and development from about the 4th-5th centuries BCE until the eve of the Gallic wars. Why do we have such detail about the structure and arrangement of these sanctuaries? Because the Gauls of these tribes committed a kind of religious suicide before Caesar’s onslaught came.

During Caesar’s period in the middle of the first century BCE, these sanctuaries were abruptly closed. The hollow altars were filled in and covered over. The temples were dismantled – their walls collapsed inward to cover their contents. The ossuary shrine made of ancestral bones was carefully knocked outward from the inside, so gently that many of the bones remained locked together in their stacked patterns, and none were broken. Everything was leveled, including the palisade walls; the banks were knocked over to fill in the boundary ditches. And then the entire enclosure was covered over with a low mound of soil. This was not the destruction of war – the sanctuaries were intentionally and carefully dismantled, and all around the same time, mid-century. As the Druidic priesthood of Gaul saw what faced them in Caesar’s conquest, they chose to bury half a millennium of religious tradition literally into the grave rather than see it desecrated by the Roman legions.

I try to imagine what that must have been like. Some handful of individual Gaulish people did the physical labor of knocking down the ossuary temple built of twenty-five generations of their own ancestors’ bones, obliterating five hundred years of memory and tradition and worship, knocking them into the dirt as gently as possible and covering it over, never to be retrieved. And then what… walked away? Went for a beer? Joined Vercingetorix’s army? Drowned themselves in the river? That’s about the point where I give up trying to imagine what it must have been like to have to do that.

When Caesar came, he never saw the temples, because they were gone before he arrived. He wrote about Gaulish religion, of temples with sacrificial deposits in them, but scholars recognize his texts as copied from the earlier writer Poseidonius. What he saw he described as “constructed mounds” which he understood were made up of sacrificial deposits. The grave mounds of Gaulish religion.

It is from this period that the springs, caves, lakes, and other natural sites began to dominate as centers of cult activity in continental Celtic religion. It is from this period that we see a dramatic increase in votive icons and offerings, magical tablets, and other religious items appearing as the evidence of folk religion. Because after the destruction of the temples and the criminalization of Druidic religion and its public rites, private worship in the hidden places of nature was what the Gauls had left to them.

The Gauls did not forget, though. After the Roman conquest, even following the official prohibition on Druidic religious activity, the sanctuaries continued to be kept as sacred ground. While the dunums were built up into Roman oppida all around, the grounds on which the sanctuaries stood were kept empty. No longer visible as mounds, with no surviving structures traceable on the ground surface, the people somehow passed down a hidden tradition about the sacredness of these sites for four hundred years after the conquest, protecting the boundaries of the sanctuaries from the encroaching city. It was not until the fourth century CE that a new temple, now in the Romanized style, was built – and when it was, its corner posts were laid precisely onto the invisible footprint of the old Gaulish temple.

That is the story that the ghosts of Gaul asked me to tell you tonight.