IT IS a timeless tale that has been cherished by generations of spellbound schoolchildren: a mighty force of Roman troops disappears without trace after marching into Scotland to subdue rebellious Celtic tribes.

As a Glasgow schoolboy, Kevin Macdonald was among those who fell in love with The Eagle Of The Ninth. Years later, as the director of Oscar-winning movie The Last King Of Scotland, he is on the verge of realising his ambition of transferring the story to the big screen.

After several false starts by other directors, Macdonald believes he will be the first to make a feature film of Rosemary Sutcliff's celebrated historical yarn. He wants to create a swords-and-sandals "western", filmed on location in Scotland, in which the Romans speak with American accents.

Sutcliff's 1954 novel is set in Scotland after the building of Hadrian's Wall and recounts the story of a young Roman's search to discover the truth behind the disappearance of his father, who was a member of the Ninth Legion.

The 4,000 elite Roman troops marched into Scotland in a bid to subdue the pugnacious indigenous Celtic tribes but, according to legend, they vanished without trace and were never seen again.

Sutcliff's book sold more than a million copies and was made into an acclaimed BBC television serial, shot in Aberdeenshire in 1977, and a Radio 4 drama.

Macdonald, who directed Touching the Void, which told the story of a disastrous expedition to scale a treacherous Andean peak, feels the time is right for the work to be recreated for a new generation. He told Scotland on Sunday: "I am definitely going to return to Scotland to direct a film version of The Eagle Of The Ninth. It is a book that I absolutely loved as a child.

"We are beginning to think about the cast and the idea is to use American actors for the Romans and to use Scots and other Celts for the Pictish people.

"It is a part of history that has never been seen on the big screen before and that is why it is so exciting."

The two-time BAFTA-winning director said he wanted the end result to be a mixture of epic costume drama and the classic John Ford cowboy film The Searchers from 1956. "The idea is to create a Scottish Western," he said.

Macdonald, who hopes to start work on the project next year, will be working with Duncan Kenworthy, the London-based producer of Four Weddings And A Funeral and Love Actually.

The script is currently being written by Jeremy Brock, who co-wrote The Last King Of Scotland, the Victorian epic Mrs Brown starring Billy Connolly and Dame Judi Dench, and the Second World War drama Charlotte Gray which featured Cate Blanchett.

The budget for the film is expected to be around the same as, if not more than, the relatively modest £3m which was spent on Macdonald's take on Idi Amin's descent into bloody tyranny and madness as president of Uganda.

The origins of the real Ninth Legion are uncertain, though it distinguished itself in Spain around 24BC and became known as the Legio IX Hispana. It also served in Germany, Hungary and Africa, before probably joining the 40,000-strong army assembled to invade Britain in 43AD.

There is evidence to suggest the Ninth was stationed at Eboracum (York) from 71AD. But the Romans never subdued the northern Celtic tribes - variously referred to as Brigantes, Caledonians and Picts - who repeatedly launched raids into the mighty Roman Empire. The Romans began construction of Hadrian's Wall around 120AD, in an attempt to keep the hordes at bay. It is much the same time the Ninth Legion disappears off the page of history, with many concluding they must have been sent to Scotland and were slaughtered by the ferocious paint-anointed mountain warriors.

Macdonald's immediate project is a lavish Hollywood adaptation of the BBC political thriller State Of Play. "Brad Pitt is taking the role played by John Simm from Life On Mars and the setting has been moved from London to Washington," he said.

"The big challenge for me is that the original version was so good. To create something that won't be compared unfavourably to the BBC production is a considerable task."

British scriptwriter Paul Abbot, who was behind the hit Channel 4 show Shameless, will be executive producer of the American production.

Macdonald revealed he is an admirer of Shameless, which chronicles the misadventures of the work-shy Gallacher family in Manchester.

"I am a big fan of Shameless and James McAvoy's performance in the early episodes was one of the main reasons why I cast him in the Last King Of Scotland," he said.

In 2003, two other filmmakers announced they planned to use the Ninth Legion as the basis for films.

Neil Marshall, who wrote and directed the Scottish-based horror hit Dog Soldiers, wanted to create a historical action thriller with the Picts slaughtering the Italian invaders.

Ros Borland and Catherine Aitken, the producers of the BBC TV show Afterlife, unveiled plans for a gory epic titled Legion. So far neither film has made it to the big screen.