The tragedy of King Arthur is one segment of a vast cycle, the 'Matter of Britain, ' stretching across generations of early British kings. Vortigern is central to this cycle. King two generations before Arthur, he opens Britain to the Saxons, ancestors of the modern English. Rising from humble roots, he takes centre stage at court in a crisis moment, plays and loses a vicious game of Dark Age power-politics, and is driven into exile in mountain wilderness, there to encounter dragons, demons, prophecy and a child who turns out to be Merlin