The film project was initiated by Etienne Comar in 2006, when the tenth anniversary of the incident made it a topic again in French media. Comar, a film producer by profession and a Catholic, had been fascinated by the monks since the earliest news of the abduction, but felt that their death had overshadowed what he thought was really interesting: why they had decided to stay in Algeria despite the ongoing Algerian Civil War. Comar contacted Xavier Beauvois in 2008 after having written a draft, and together they continued to work on the screenplay. The two researched, met with theologians, and during a break Beauvois chose to live for six days at the Tamié Abbey in Savoie. Some inspiration was taken from writings by two of the Tibhirine monks, Christian de Chergé and Christophe Lebreton. Franco-American monastic consultant Henry Quinson was asked to correct and add historical and liturgical content for further authenticity. The script was later sent to relatives of the deceased monks, most of whom reacted positively to the project.