In December 2013, I inaugurated a project to catalogue the Coptic and Arabic manuscripts at the Monastery of the Syrians in Wādī al-Naṭrūn, Egypt. As of December 2014, my team and I have produced entries for 140 out of approximately 800 manuscripts. The purpose of this paper is to present a preliminary report on our findings. First, I will summarize the contents of the collection, classified by the monastery into seven traditional genre divisions: biblical texts (kutub muqaddasah), commentaries (tafāsīr), church canons (qawānīn), theology (lāhūt), ascetic literature (naskiyāt), saints’ lives and sermons (mayāmir), and liturgy (ṭuqūs). Second, I will introduce our cataloguing method and present a case study: a thirteenth-century Coptic-Arabic manuscript containing the Psalms, assorted biblical and liturgical prayers, and the early Christian correspondence between Jesus and King Abgar. This manuscript is important for historical, textual, and codicological reasons. First, it was funded in Cairo by the well-known medieval literary patron al-Amjad Ibn al-‘Assāl and produced in 1255 CE by his personal scribe Gabriel, who later became Coptic Pope Gabriel III (fl. 1268–1271). Second, its bilingual text of the Jesus-Abgar correspondence preserves the second oldest extant copy of that work in Arabic. Third, in the late eighteenth century, the manuscript was divided, with the Psalms bound in one volume (classified under biblical texts as MS 11) and the rest relegated to a second volume (classified under liturgical texts as MS 383). Our cataloguing work has allowed us to reunite the two halves codicologically and reconstruct their shared history.