La fuite des Iyād au « Pays des Romains » : une théorie de migration transfrontalière aux débuts de l'Islam.

This paper analyses the narrative sources dealing with a unique phenomenon in early Islam: the passage of part of the Arabic-speaking Iyād group into Roman service. Abbasid-era authors (132/750-333/945) locate and date the defectors in the context of the conquests (futūḥ) of the Roman and Sassanian Middle East by earlier Arab-Muslims (c. 10/632-20/642). We highlight the contradictions, inconsistencies and anachronisms of the versions, and focus especially on their tendency to actually deal more with migration from Iraq to northern Syria than from northern Syria to Byzantine Anatolia. Thus, we propose an alternative scenario: the Iyād gradually settled in the northern military district (ǧund) of Homs, in ex-Roman Syria-Mesopotamia during the first/seventh century. Considering the similar events involving emigrant, defector and rallied units during the Umayyad period (40/661-132/750), as well as the frequent shifts of the frontier in the border zone (ṯuġūr), we suggest that the Iyād, like many groups driven out and conscripted into the region by both the Byzantines and the Umayyads empires, may have passed repeatedly into the service of both. Eventually, the rigidification of geographical, political and confessional borders transformed such opportunistic and/or forced movements, although still attested, into unnatural apostasies. However, this context prevailed in the writing of the narrative sources on their primordial flight to the "land of the Romans". [ABSTRACT FROM AUTHOR]