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.
Until then, Syria was the primary center of Eastern Orthodox Christianity. Conversion to Islam was almost non-existent prior to the invasion, except among Arab tribes already living in Syria; specifically, these included the Ghassan tribe which converted.