The FWF ESPRIT project “Shaping Christian Ritual in the Multilingual World of Late Antiquity: The Case of the Anaphora of St Mark” (ESP 7862124) will combine papyrology with manuscript work, liturgical studies with social historical research to explore the anaphora of St Mark, the longest documented Christian prayer still in use. This prayer is known from 19 late antique papyri, which preserve parts of it or closely related prayers, as well as from medieval manuscripts in Greek, in Sahidic and Bohairic Coptic, in classical Ethiopic, and in Arabic, and it is occasionally still used by the Coptic Orthodox Church. This unparalleled wealth of documentation allows us to follow the textual history of this anaphora in detail, which remains impossible for other Christian anaphoras. Through its numerous late antique sources, we can observe a dynamically changing liturgical text between orality and writing. These observations can bring novel insight into the mechanisms of anaphora development in late antiquity. My project will provide new editions of papyri and manuscripts of the anaphora as well as answer some questions concerning the anaphora in case studies.