Benjamin Scheller is Professor of Medieval History at the University of Duisburg-Essen. In the Winter Term 2025/26, he was a POLY Writing Fellow in the Writing Group "(Re-) Ordering Time." During the group's meetings at Forschungskolleg Humanwissenschaften Bad Homburg in January and June 2026, he developed his contribution to the first volume of POLY's forthcoming three-volume book project, Doing Christianity: A Praxeological Guide to Polycentricity and Plurality of Premodern Christianities.