The real-life hero of this summer’s blockbuster movie Dunkirk, which portrays the valiant effort of naval officers and civilians to evacuate more than 300,000 Allied soldiers trapped by the Germans during the Second World War, was a Canadian who grew up in Montreal and attended McGill University.

Yet the name of James Campbell Clouston, who is credited with saving close to 200,000 soldiers as German planes bombed and strafed the pier while he calmly ushered troops onto ships for five days, is never mentioned in the film and remains largely unknown in Canada.

US Marines were driven into submission by their British counterparts during a training exercise held deep in the California desert last week, according to a report in Britain's Daily Telegraph newspaper.

The paper reported the group of Royal Marines employed new tactics that helped them get the better of the American troops, who were on home soil.

According to The Telegraph, Exercise Green Dagger involved the two nations facing off against each other in a competition in which the sides were tasked with taking out one another's assets.

The Royal Marines "dominated" the US in the five-day simulation, it said, with US forces asking for a "reset" less than halfway through.

At one point, the Royal Marines had taken out or disabled almost all the US assets, The Telegraph said.

The Royal Navy told Insider that the victory was decisive.

In a statement, it said the mock battle "concluded with a last-minute 'enemy' assault which was repelled, leaving allied forces in control of over two thirds of the entire 'battlefield.'"

The navy said the British commandos "won decisive battles early on and gained ground from their enemy, but, with the US Marines pushing into allied territory, Royal Marines and their allies carried out raids behind enemy lines to stop further counterattacks."

The UK forces celebrated online in the aftermath.

A tweet on Saturday by 40 Commando, a subdivision of the Royal Marines, said UK forces triumphed in "an epic close quarters finale."