During the years 500 - 550AD the Britons appear to have held back the Saxon advance. However, in the following years they were forced back into Cornwall and Wales. The territory held by the Saxons eventually became known as England and the people in Wales were called 'Welsh' from the Saxon word 'weala' meaning 'foreigners'. (It's worth noting that the Welsh called themselves 'Cymry' meaning 'fellow countrymen' and their country 'Cymru'.) Now, the importance of this division is that the Saxon conquerors were hardly likely to be interested in the exploits of a 'foreign' leader who was successful in holding them at bay. Maybe it is for this reason that Arthur is not mentioned in early English chronicles while his name occurs in Welsh ones.
The first reliable reference to Arthur is in the 'Historia Brittonum' written by the Welsh monk Nennius around the year 830AD. Surprisingly he refers to Arthur as a warrior - not a king. He lists twelve battles fought by Arthur including Mount Badon and the City Of The Legion.
Arthur is mentioned in early Welsh literature, however the surviving manuscripts which refer to him date from after the legend was firmly established. These documents, though interesting, do not help us understand the roots of the legend.
It was the work of Geoffrey of Monmouth, another Welsh cleric, which really set down the foundations of the Arthurian legends. Other subsequent writers have expanded his themes and added new strands to the story. His work, 'Historia Regum Britaniae' was written in the year 1133AD. He claimed to have based the work on an ancient Celtic document in his possession. It became a 'best seller' and still survives in two hundred manuscripts.
Geoffrey's work was intended to be an historical document. Within fifty years of its completion it had fired the imagination of writers of fiction across Europe. Many of these added new strands to the story which subsequently became essential elements:
In 1155 the French poet Maistre Wace added The Round Table.
Chretien de Troyes, also French, wrote five Arthurian stories between the years 1160 and 1180. He developed the theme of chivalry and dwelt on the subtleties of courtly romance.
Another French man, Robert de Boron from Burgundy, developed the idea of the Quest for the Holy Grail.
Back in England at about the same time, (around 1200AD) the priest Layamon wrote the story in English - the first time it had appeared in this language. In his version Arthur did not die from his wounds, he remained on the Isle of Avalon - to return some time in the future.
In 1485 William Caxton published 'Le Morte Darthur' - one of the first printed books. Written by Sir Thomas Malory, this was a collection of eight stories which brilliantly drew together the whole saga and gave us the account we know today.
It is interesting that writers placed Arthur in their own times. In fact the way the whole story develops tells us far more about the times in which the author lived than the era referred to.
Prior to the Norman invasion the Vikings were attacking and settling just as the Saxons had done 400 years before. People must surely have looked around for a saviour. Times were right for telling stories of a powerful leader.
The Norman conquerors must have welcomed Geoffrey's account. This suggested that the rightful heir to the throne of England was driven out by the Saxons - maybe to Northern France. They could claim a direct blood-line to previous kings.
Geoffrey dedicated his book to Robert, Earl of Gloucester, Lord of the Gwent Marches. Robert was unusual among the Norman Lords in as much as he encouraged an intellectual movement in Wales. It is said that he gathered a brilliant body of learned men in his court. He must have welcomed Geoffrey's account which located important events in Caerleon (part of the Gwent Marches) and stated: "the city contained a college of two hundred learned men, who were skilled in astronomy and the other arts and so by their careful computations prophesied for King Arthur any Prodigies due at that time." Geoffrey later became Archdeacon of Monmouth!
Geoffrey's writing obviously touched a nerve particularly in France. Maybe it was because it harkened to a 'better time'. In reality life must have been very different from that depicted in the legend that developed.
The story as we know it was written by Malory in 1470. He very clearly set the events in the Middle Ages.
What is the truth? Is there such a thing as the truth? Locating facts is very difficult. Geoffrey was writing some 600 years after the events. His main source is not known. Until relatively recently there was no standard spelling for even common words - names of people and places in particular took many forms. So 'creative' researchers can find what they want to find, while sceptics find nothing they can call concrete evidence. The deeper you dig, the less you see. Remember the words of a popular song:
"Don't push too far, your dreams are china in your hand."