This case study focuses on changes in the initial representations of Secondary 3 students (n = 53) before and after the implementation of a learning sequence related to Charles called Charlemagne. This sequence proceeded by comparing excerpts from a fictional television series with primary and secondary sources. The literature recognizes the potential of historical films to reveal and criticize representations of the past. But do these filmic resources modify students’ representations or prior knowledge? The results show that the students modified 72.2% of their erroneous representations with regard to historiography and developed new knowledge (21 knowledge, 346 occurrences) in line with this historiography. Sixty-one percent of these were referred by the students to the television film.