King Arthur or Arthur Pendragon is a legendary British king or war-leader who is alleged to have led the British defence of England and Wales from the Saxons.

In 410 AD the Romans pulled out of England in a realisation that they could no longer commit the resources needed to hold Britain against streams of invading Germanic tribes, notably the Saxons, the Angles and the Jutes. Thus, the Britons, the ancient people of Britain and the rump of the Roman colony were left to defend themselves against marauding armies of these Germanic tribes. Chaos reigned in lower Britain as a result for much of the fifth and sixth centuries and it was out of this chaos, known as the Dark Age of Sub-Roman Britain, that the story of King Arthur emerged.

As with many other national myths it is possible that there was an actual character on which Arthur was based, but this was soon eclipsed by the mythical figure which in the course of the Early Medieval Period and High Middle Ages emerged in the epic cycle known as ‘the Matter of Britain’. This relates how Arthur defended England against the Saxons and other Germanic marauders by leading a fellowship of knights known as the Knights of the Round Table. If there was a historical figure known as Arthur Pendragon he was probably Welsh.

Later versions of the Arthurian legend became more and more elaborate from the eleventh and twelfth centuries onwards, with writers such as Chrétien de Troyes adding the figure of Lancelot du Lac (of the Lake) and a quest for the Holy Grail from which Jesus had drank at the Last Supper. Other embellishments included the appearance of a famed sword known as Excalibur which Arthur pulled from a stone to assert his right to be King of the Britons in succession to his father, Uther Pendragon.