Still, almost every writer of note has had something to say on the subject, and thus the Arthuriana has become almost as voluminous as the Shakespeariana.
The legend of Arthur, almost unknown before the twelfth century, so rapidly became popular all over Europe, that it was translated into every language and recited with endless variations at countless firesides.
Robert de Borron is said to be mainly responsible for the tale of Merlin, the real poet of that name having been a bard at the court, first of Ambrosius Aurelianus and then of King Arthur.

The Merlin of the romances is reported to have owed his birth to the commerce of a fiend with an unconscious nun.

A priest, convinced of the woman's purity of intention, baptized her child as soon as born, thus defeating the plots of Satan, who had hoped the son of a fiend would be able to outwit the plans of the Son of Man for human redemption.

In early infancy, already, this Merlin showed his miraculous powers, for he testified in his mother's behalf when she was accused of incontinency.
Meantime Constance, King of England, had left three sons, the eldest of whom, Constantine, had entered a monastery, while the two others were too young to reign.

Drawn from his retirement to wear a crown, Constantine proved incapable to maintain order, so his general, Vortigern, with the aid of the Saxon leaders Hengist and Horsa, usurped his throne.