the city's walls demolished. In 750 a revolt, led by Majza'a ibn al-Kawthar and Umayyad pretender Abu Muhammad al-Sufyani, against the new Abbasid Caliphate swept across Syria; the tribes in Palmyra supported the rebels. After his defeat Abu Muhammad took refuge in the city, which withstood an Abbasid assault long enough to allow him to escape. Late kingdoms The Ghassanids, Lakhmids and Kindites were the last major migration of pre-Islamic Arabs out of Yemen to the north. The Ghassanids increased the Semitic presence in then-Hellenized Syria, the majority of Semites were Aramaic peoples. They mainly settled in the Hauran region and spread to modern Lebanon, Palestine and Jordan. Greeks and Romans referred to all the nomadic population of the desert in the Near East as Arabi. The Romans called Yemen "Arabia Felix". The Romans called the vassal nomadic states within the Roman Empire Arabia Petraea, after the city of Petra, and called unconquered deserts bordering the empire to the south and east Arabia Magna. The Emesene were a Roman client dynasty of Arab priest-kings known to have ruled from Emesa, Syria. Roman empress Julia Domna, matriarch of the Severan dynasty of Roman emperors, was one of their descendants. The Lakhmids as a dynasty inherited their power from the Tanukhids, the mid Tigris region around their capital Al-Hira. They ended up allying with the Sassanids against the Ghassanids and the Byzantine Empire. The Lakhmids contested control of the Central Arabian tribes with the Kindites with the Lakhmids eventually destroying the Kingdom of Kinda in 540 after the fall of their main ally Himyar. The Persian Sassanids dissolved the Lakhmid dynasty in 602, being under puppet kings, then under their direct control. The Kindites migrated from Yemen along with the Ghassanids and Lakhmids, but were turned back in Bahrain by the Abdul Qais Rabi'a tribe. They returned to Yemen and allied themselves with the Himyarites who installed them as a vassal kingdom that ruled Central Arabia from "Qaryah Dhat Kahl" (the present-day called Qaryat al-Faw). They ruled much of the Northern/Central Arabian peninsula, until they were destroyed by the Lakhmid king Al-Mundhir, and his son 'Amr. Medieval period Arab caliphates Rashidun era (632–661) After the death of Muhammad in 632, Rashidun armies launched campaigns of conquest, establishing the Caliphate, or Islamic Empire, one of the largest empires in history. It was larger and lasted longer than the previous Arab empire of Queen