On the one hand, local historiography fixated in writing and thus preserved the notions of its own past, which were an important part of the local identity, and on the other (co-)created them to an equal extent. By way of example of the oldest ecclesiastical history of mediaeval Grado and Split, which associates both cities with ancient Aquileia and Salona, the treatise highlights the question to what extent local historiography (co-)created local identity and the related historical tradition