Cadbury Castle, in Somerset, England, doesn't look like much today--just a terraced hill with some faint outlines of defensive ditch-works. But the site attracts a large number of curious tourists each year because, according to local legend, it is the location of the legendary King Arthur's Camelot.
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Cadbury Castle is not actually a "castle". There are no walls or towers or moats, and it was constructed centuries before the earliest motte-and-bailey castles appeared. Cadbury is actually a hilltop fortress, similar in construction to pre-Roman ditch-and-bank citadels that have been found elsewhere in England.
Most of what we know archaeologically about Cadbury Castle comes from a series of digs carried out in the 1960's. Flint tools and stone flakes show that this spot was first occupied at least 5000 years ago. These Neolithic inhabitants were then replaced by a Bronze Age settlement. While the top of the hill had a number of buildings at this time (made with wooden posts), there is no evidence for any fortifications. But the hill gives a commanding all-round view of the surrounding countryside, so it is no surprise that it was apparently turned into a fortified site in around 500 BC, during the early Iron Age. A series of four concentric ditches were dug, with the soil piled up behind to form ramparts. These would have had wooden fences running along the top, and a series of wooden buildings inside the innermost enclosure. A series of staggered gates through the walls, probably fortified by towers, would have allowed access. The remains of metal-working forges have been found, as well as the post-holes for both round and square buildings. It is not known which of the several early Celtic tribes in the area first built the Castle; the Durotriges and Dumnoni both lived in the area. Over the next few centuries the defensive structures were moved around and rebuilt at least five times.
When the Romans invaded Britannia in 43 BCE, Cadbury Castle apparently was a center of resistance: Roman artifacts have been found at the fort dating to this time, and the foundation of a typical pallisaded Roman Army fort has been uncovered at the top of the hill inside the ditches. Apparently the Castle was taken by the Romans in battle, and occupied by one of the Legions. They did not stay long, though--the artifacts disappear after about 50 BCE, and the entire hill seems to have been abandoned for the next 400 years. Although there were early rebellions against Roman rule by Caractacus and Boudicca, the period of Roman occupation was mostly peaceful, and the Romans did not have much need for fortified positions.
As the Roman Empire declined during the 4th Century CE, the province of Brittania became more and more neglected. The Legions were withdrawn, the Roman administrators and tax collectors left, and the Britons were abandoned and left on their own. Around the year 450 CE, the Saxon tribes of northern Germania, attempting to take advantage of the situation, invaded and took over most of southeast England. At about this time, the long-abandoned fortress at Cadbury was re-occupied, perhaps by the Dumnoni tribe. A large ceremonial hall was built on top of the hill, and a new ring of defensive walls several feet thick (made of stone rubble taken from Roman buildings) was added, with a strong gatehouse at one end. No trace of these structures remains today. Traces of pottery from as far away as the Mediterranean were found, however, indicating that the hilltop fortress was held by a very wealthy and militarily-powerful local ruler.
And it is here that legend and history intersect. The Saxon conquest of Somerset was delayed at least 50 years by fierce local resistance, and the fortifications at Cadbury Castle probably played a role in this. None of the other remaining Iron Age hilltop forts in England was re-occupied by the post-Roman Britons, and it seems likely that this was done at Cadbury in response to the Saxon military threat. According to later legend, the leader that arose to lead this resistance was King Arthur Pendragon. With his force of knights, King Arthur drove out the Saxons and established a British kingdom with its center at the grand castle of Camelot.
It is important to note that none of the Arthurian legends appeared until the medieval times, almost a thousand years later, and the stories reflect the period in which they were written, not the times in which they supposedly took place. The great stone castles, mounted knights in plate armor, and chivalric code of honor described in the Arthurian stories all belonged to the 15th century, not the 5th.
Archaeologically, there is little evidence for a battle at the fortress. Instead, after the Saxons successfully conquered the rest of England, Cadbury Castle seems to have been simply abandoned for a number of centuries. Around the year 1010, the Anglo-Saxon King Ethelred II established a mint on the top of the hill for striking silver coins, which continued into the reign of his successor King Canute. The site was abandoned for good in around 1020 CE. A few medieval farmers ploughed some of its terraces.
But to medieval scholars, Cadbury Castle, as an obvious fortified place where a powerful local ruler made a military stand against the Saxons, was enough to tie it to the Arthurian legend. In local lore, the hill became the site of the mythical Camelot (the local river was the Cam, but it's unclear if that name came before or after the legend). When a member of King Henry VIII's court named John Leland visited Cadbury in 1542, he heard all the local tales and published them; soon maps began appearing with the name "Camelot".
Today, both Cadbury Castle and the nearby village of Glastonbury are popular tourist destinations, trading on their association with the Arthurian legends.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)