The late antique papal letters addressed to the Church of Arles are known to us today through their transmission in libri canonum from the 7th century, four manuscripts of the Collectio Arelatensis dating from the 9th, 11th, and 12th centuries, as well as several copies from the late 15th and 16th centuries. This collection, comprising fifty letters from eleven popes of the 5th and 6th centuries, three requests addressed by bishops of southern Gaul—two of which were sent by Caesarius of Arles—to the Roman See, and an edict of the emperors Honorius and Theodosius II, represents a unique case of a late antique epistolary corpus associated with a particular church. While the original processes of compilation and preservation of these writings remain unclear—was the Collectio Arelatensis the result of an initiative from Arles or from Rome?—their transmission over the centuries attests to a well-established archival practice based on the identification, selection, organization, and copying of documents. The study of the preserved witnesses reveals how these processes led to successive acts of memorial reappropriation in different contexts, contributing to the long-term construction of an ecclesial identity. This paper aims to examine the surviving manuscripts in order to highlight the issues related to their production and use, intertwining material history, archival practice, and institutional memory.