The action of the patriarch Severus (ca. 465-538), during his pontificate in Antioch (512- 518) and during his exile to Egypt (518-538), is very well documented by Syriac and Greek sources, for this great bishop was the key opponent to chalcedonism in the Roman East, in the early 6th century. Among this abundant literature, a small dossier stands out attesting to his concern for the Christian community of Ḥirta of Noʿman (al-Ḥīra), even though it was established beyond the limits of the Eastern Roman Empire and the patriarchate of Antioch. It contains: 1) a fragmentary letter by Severus himself addressed to this community; 2) a missive from the Severan metropolitan and theologian Philoxenus of Mabbug (Manbiğ) addressed to a local potentate, the stratelates Abū Yaʿfūr, the immediate predecessor of the Lakhmid amīr al- Munḏir III at al-Ḥīra; 3) the story, told by the Byzantine historian Theodorus the Lector, of an embassy by two bishops that Severus sent to the latter. A synopsis of these three documents is presented to shed light on the issues at stake in the policies of Severus towards the Christianized Arabs on the borders of the Roman and Persian Empires. Indeed, his action must be understood both in the context of the dogmatic conflicts underway within Christianity and in the more general perspective of the policy of the Eastern Roman Empire vis-à-vis Sassanid Persia.