Mother and Father Die Tragically, but her son becomes The Boy Who Lived.

Clue 1: the son is not the main character.

Clue 2: it is not on this list: https://en.m.wikipedia.org/wiki/Category:Films_about_orphans

Clue 3: there are no animals involved.

EDIT: it's been two hours and I have to get on with preparing for Xmas, so I'm going to give one final clue which hopefully will be so obvious someone will get it. Here is it is:

Clue 4: IT'S SET IN THE 1940s AND INVOLVES NAZIS