This article explores late antique material evidence of Christianity in northern Mesopotamia, focusing on epigraphic and iconographic sources to trace its gradual integration into Roman society. Organised into two main sections, the study synthesises recent scholarship to contextualise these developments within the region’s commercial, military and cultural frameworks. Particular attention is given to addressing the imbalances in historical and archaeological visibility between urban centres and rural areas, drawing on findings from intensified research in northern Mesopotamia over the past two decades. The text provides a previously missing compilation of the region’s known late antique Christian inscriptions, paintings, carvings and mosaics. It discusses key themes, such as the interplay between Syriac and Greek as epigraphic languages, featuring the predominance of Greek inscriptions in cities like Edessa, Tella and Nṣībīn, alongside a gradual rise in Syriac epigraphy in rural areas by the sixth century. It also examines linguistic and symbolic markers of Christianisation, including the increasing use of crosses, monotheistic declarations and the adaptation of pre-existing visual motifs into Christian iconography. Finally, by integrating GIS data, the study delves into religious transformation’s spatial and socio-cultural dimensions in late antique northern Mesopotamia.