The research further suggests Arthur's story was later embellished and relocated. The legend, featuring the wizard Merlin and the Knights of the Round Table, became a famous tale around the world.
Robin Crichton, the Scot who recently concluded the eight- year development of a successful Charles Rennie Mackintosh Trail in France, will develop the Arthur trail along with tourism bodies. He believes it could generate at least £12.5 million in tourism revenue in its first year alone.
Mr Crichton said: "Arthur was born in the latter half of the 5th century. He became the commander of a rapid reaction force of British cavalry, originally created by the Romans but which had continued after their withdrawal.
"Arthur's career started in Strathclyde, where struggles between rival rulers had allowed the Southern Picts to occupy the Lennox. Arthur seems to have settled the succession, taken back the lost territory and probably then advanced to overrun the Pictish forward positions, forcing a peace.
"This was something the Romans had never achieved and it was a feat which made his reputation.
"He fought as a crusader and in his wake followed Christian missionaries bringing moral authority to hold the peace."
Mr Crichton continued: "Invited to combine with British infantry in the south, Arthur then led a confederate army against first the Angles, and then the Saxons, successfully halting the German invasion in its tracks and bringing peace on every front to the whole of Britain – a peace which held for two generations.
"His final days were a story of infidelity and betrayal and he probably died at St Ninian's monastery in Stirling."
At the National Library of Scotland tonight, Mr Crichton will launch his book On the Trail of King Arthur, which aims to "finally banish the myths and tall tales to reveal the truth behind the legend". It pieces together what is known about Arthur from socio-political events at the time and oral tradition. The book, which precedes the trail, features maps and itineraries alongside evidence and alternative theories relating to featured sites.
Exploratory archaeological digs will be followed by experimental centres recreating a Dark Age environment and providing hands-on experience of lifestyle, culture, and crafts around a programme of events geared to the Celtic calendar.
Educational and heritage groups are involved in these developments and a leading firm of heritage consultants will mastermind the archaeology.
Mr Crichton said: "King Arthur and the Knights of the Round Table is one of the world's great legends. For more than 1000 years the story of Arthur has been adapted by successive generations to fit the morality and colour of their own age. It is perhaps the longest-running soap opera in literary history.
"The real Arthur lived around the turn of the sixth century, a time of oral rather than written tradition. It was an age when scribes were few and far between, and history was passed on through word of mouth by successive generations of bards.
"Then, over the centuries, in the process of recopying, those original accounts were embellished and relocated from forgotten to familiar places and made more relevant to the times."
He added: "Arthur's Britain represents a blank spot in existing history books. These are perhaps the darkest times in British Dark Age history – the Forgotten Times."