Searching for King Arthur Again

Alice Roberts’ new series, Lost Grail, revisits one of Britain’s most enduring questions: how much of the Arthurian tradition is rooted in real landscapes, real leaders, and real moments of crisis? Her approach—clear-eyed, evidence-led, and grounded in archaeology—offers a timely reminder that legends often emerge from periods of profound uncertainty.

Prof Mark Horton and I explored the same question surfaced during field trials whilst preparing for heritage work in Mali. We were testing high‑resolution 3D aerial survey methods at a Roman site in Cirencester. The technology is simple, fast, and non‑invasive, ideal for places where excavation is difficult. What it revealed was a landscape that sits squarely within the world Roberts explores: the final decades of Roman Britain and the fragile emergence of the stories that would become the Arthurian cycle.

Corinium: A City at a Turning Point

In AD 296, the Diocletian Reforms divided Britain into four provinces. Corinium—modern Cirencester—became the capital of Britannia Prima, then the most prosperous part of the island. Its amphitheatre, with space for nearly 7,000 people, was a major gathering point for a town of only 10,000.

When Emperor Honorius withdrew Roman troops in AD 410, cities like Corinium were left exposed. Coin circulation collapsed; by AD 430, barter had replaced currency. It was in this unsettled world that early sources hint at a leader capable of resisting new waves of conflict. Gildas describes a “successful warrior king,” while the Historia Brittonum lists twelve battles fought by Arthur, culminating in Badon. The Annales Cambriae and Y Gododdin add further fragments.

None of these texts give us a clear Arthur. But they point to a moment when a strong local leader could have shaped events decisively.

Aerial Evidence and an Old Question

Our aerial survey showed how the amphitheatre at Cirencester could have been adapted into a fortified stronghold. Excavations have already revealed postholes typical of fifth‑century defences. From above, the scale and strategic potential of the site are unmistakable. The images below show how the amphitheatre might have looked, the amphitheatre as it is today and the flight plan to capture it in 3 dimensions.

Was this Camelot? We cannot say. But the physical evidence aligns with the kind of power centre described in the early sources. Corinium was wealthy, strategically placed, and suddenly responsible for its own defence.

Why Roberts’ Series Matters

Lost Grail does not chase relics for their own sake. Instead, it examines how stories take shape—how landscapes, archaeology, and memory combine to form the narratives that define a culture. The Arthurian tradition is one such narrative: part history, part myth, and deeply embedded in Britain’s sense of itself.

Our Cirencester field trial offered a small but telling example of how modern tools can illuminate these older stories. Aerial surveys reveal patterns invisible from the ground, allowing the landscape to speak for itself.

In that sense, the search for Arthur continues—not as a hunt for a single figure, but as an exploration of how Britain’s identity was forged in the centuries after Rome withdrew. Roberts’ series, and the evidence emerging from places like Cirencester, show that the past still has more to reveal.