Auctor was a fifth-century bishop of Metz who lived during the era of Attila's invasions. While historical details regarding his origins and specific life are scarce, he is traditionally identified as the thirteenth bishop of Metz. He is widely venerated as a saint and is notably recognized as the patron protector of Braunschweig. His legacy is deeply tied to the city, where he is credited with intervening to save the population from siege in the year 1200.