By Jane Crowther BBC News Online

In the last couple of years there has been a slew of World War II films - many of which have been criticised for their so-called "re-writing" of history.

Dark Blue World also attempts to re-dress historical balance by telling the little known true story of the numerous Czech pilots who escaped Nazi-occupied Czechoslovakia to fight alongside the Allies in the Battle of Britain.

About 3,500 Czech and Slovak military personnel joined the British war effort after France became occupied in 1940.

The film attempts to acknowledge the contribution of Czech soldiers

The pilots among them joined the RAF voluntary reserve and two Czech squadrons were formed for the Battle of Britain.

By the end of the war, 840 pilots had died and those returning to their countries were treated as traitors by the new Communist regime and were imprisoned.

Dark Blue World's Oscar-winning director Jan Sverak was determined to bring this forgotten part of the Czech Republic's history to the screen.

"These Czechoslovakian pilots were our last heroes, if we're not taking into account those who were fighting Communism," he says.

"My father was 10 when the war was over and when I was 10, he gave me the books of the pilots' memoirs and told me not to say anything at school because it was during Socialism.

"After Kolya [Sverak's last film] we were approached and offered everything we could wish for so we thought: 'Let's do this film and let's do the dream'."

Triangle

Dark Blue World follows two fictional Czech pilots, played by Kolya's Ondrej Vetchy and newcomer Krystof Hadek, in their escape from the Nazis to the airfields of the UK where both men fall in love with the same woman, played by Tara Fitzgerald.

Dark Blue World was released to great acclaim in the Czech Republic last year before that other famous World War II film featuring a love triangle, Pearl Harbor.

The movie used real World War II planes

Sverak recalls: "When Pearl Harbor came out it was promoting our movie as well because the billboards said: 'America's Dark Blue World'."

The budgets on the two films were vastly different though. Although Dark Blue World is the most expensive Czech film ever made, the budget was a fraction of Pearl Harbor's.

England was recreated in the Czech Republic to cut costs with most of the money going into the extraordinary flying scenes featuring real footage from the Battle of Britain and some of the last remaining Spitfire planes in the world.

"We were lucky to use the footage from the Battle of Britain without which we wouldn't have been able to manage some of those sequences because the aeroplanes don't exist anymore," says producer Eric Abraham.

"We had real Spitfires from The Old Flying Machine Company in Duxford and each hour of a spitfire in the air was $10,000. But we have a wonderful movie."

'Emotional'

The film has brought recognition to the Czech pilots in their country for the first time since the political changes in 1989, something star Fitzgerald is proud of.

"I was at the opening of the film in the Czech Republic and two veterans came on to the stage. It was one of the most moving things I'd ever seen because they'd never been seen," she says.

"They became very emotional and I was very pleased to be part of that."

Says Sverak: "This part of history was not in our Czech school books. We were taught that the main contribution to World War II was the Russians.

"The same way as the Americans are now spreading their ideology that the main contribution to the war was American."

Dark Blue World opens in the UK on 10 May.

An exhibition of behind-the-scenes photos from the film, and archive images from The Imperial War Museum, is on display at Proud Central Gallery in London until 26 May.