In the 1940s and early 1950s there were several films made about the exploits of Allied agents in occupied Europe, which could probably be considered as a subgenre. "13 Rue Madeleine" and "O.S.S." were fictional stories about American agents in German-occupied France, and there were a number of films based on the stories of real-life British S.O.E. agents, including "Odette" and "Carve Her Name With Pride". A more recent fictional example is "Charlotte Gray", based on the novel by Sebastian Faulks.