Complex sentence: Christian beliefs were present in the region's Arab community since about A.D.200, when Abgar VIII, an ethnic Arab and king of the Roman client state Osroene, converted to Christianity; the religion was propagated from his capital at Edessa until its destruction in 244.
Split into simpler sentences: Christian beliefs were present in the region's Arab community since about A.D.200, when Abgar VIII, an ethnic Arab and king of the Roman client state Osroene, converted to Christianity. The religion was propagated from Abgar's capital at Edessa until its destruction in 244.