Marion Cotillard was Robert Zemeckis' "only choice" to appear in 'Allied'.

Marion Cotillard

Marion Cotillard

The French actress had read the screenplay for the World War II movie long before the director was attached, but he insists he had no idea she was already interested when he offered her the part of French Resistance fighter Marianne Beausejour.

He said: "I didn't know this, but she had read the project awhile back. I don't even know if I was attached at that point. I offered it to her as soon as I became the director and she was my only choice. So I was thrilled she wanted to do it."

The 64-year-old filmmaker favours an economical approach to shooting a movie, and never goes out for more footage than he needs.

He told ComingSoon.net: "They change in the editing room, but I don't rearrange the story. I'm a very meticulous filmmaker. I shoot exactly what I need. I don't shoot a bunch of stuff and then try to build the movie afterward. I don't want to shoot any more than I absolutely have to."

The most "challenging" scene the director faced was the party, and it took months to prepare for the footage with a purpose-built set.

He explained: "There were some scenes that were more difficult. The climax took a while to do. Interestingly enough, for a directing standpoint, the most challenging scene from a directing standpoint was the party.

"There's so much going on and that scene had to be laid out months in advance.

"We actually built the set to accommodate the story. The whole house was designed around how it would function to tell the story."

Zemeckis was a World War II "buff" as a child so was delighted working on the movie helped him expand his knowledge.

He said: "One of the great benefits of being a movie director is that you get to learn a lot of useless information about a great many things.

"I'm an expert on Lysander aircraft. I know a lot about SOE operatives. What do you want to know about the STEN gun? You immerse yourself in the stuff you need to know about the era. I was a World War II buff as a child. If you're my generation, you can't get enough of World War II.

"You learn more and more about certain things and, as soon as you read a screenplay and are loving the screenplay, you want to learn what was going on through documentaries and films of the era."

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