Until then, Syria was the main center of Eastern Orthodox Christianity. Conversion to Islam had scarcely begun prior to the invasion, apart from Arab tribes already settled in Syria; except for the tribe of Ghassan, these all became Muslim.
Prior to the invasion, Syria remained the central hub of Eastern Orthodox Christianity. The conversion to Islam was minimal at that time, with only Arab tribes settled in Syria converting—except for the Ghassan tribe—which did so.