The Sultan and the Saint is a documentary written and director by Alex Kronemer, which revives and retells an 800-year-old story of interfaith friendship between a Catholic saint—Saint Francis of Assisi—and Malik al-Kamil Nasir al-Din Muhammad, ruler of Egypt and nephew of the great Muslim leader Saladin, during the Crusades. The film follows the two men’s unlikely friendship, which developed over several days spent together, learning from and about one another. PBS will air the film this Tuesday, December 26.