In 629 AD, the armies of Islam came out of Arabia and clashed
with the Byzantine army at Mu'tah in south Jordan. They were
initially repulsed, but attacked again, and the Byzantines were
defeated at the Battle of Yarmuk in August 636. The Islamic generals
marched on to Damascus and established the Umayyad Caliphate
in 661 AD.
During the Umayyad period (661 - 750 AD), Petra was on the
direct route to Mecca, and had some prosperity. When the Abbasid
dynasty transferred the capital to Baghdad in 750 AD, the city
There seems to have been a serious earthquake in 747 AD which
destroyed the city of Jerash, and caused extensive damage throughout
Jordan and Palestine. It is assumed that the final citizens of
Petra, if there were any left, abandoned the city at that time.
By this time, most of the other Nabataean cities had disappeared
from historical record as well