The secret vote that elected Pope Gregory X lasted from November 1268 to September 1271. It was the first example of a papal election by “compromise,” after a long struggle between supporters of two main geopolitical medieval factions — those faithful to the papacy and those supporting the Holy Roman Empire.

The Oscar-winning film stars Ralph Fiennes, Stanley Tucci and Isabella Rossellini and offers a fictionalized, high-stakes look at what happens behind the Vatican's closed doors.