By 525 Judaism had gained such a foothold in the Himyarite kingdom in the south that the rulers themselves began to persecute the Christian population. This was the justification which the Abyssinians (Ethiopians) used to invade south Arabia between 525 and 530, conquering the Himyarites and leaving an Abyssinian governor. By about 570, however, the Persians conquered and controlled the whole of Arabia. (Ref. 82, 222)

The western portion of this large area continued to share in the fate of Byzantium. Christian vandalism against the Jews and Samaritans1, which had started in the preceding century, now increased with destruction of synagogues and temples. An earthquake of 526 did not help matters when it killed 200,000 to 300,000 people in Antioch. (Ref. 222) The Jews and Samaritans revolted in 529 and again in 560 and finally welcomed the invasion of the Persians as they extended their empire once again about 570. The Jews took this opportunity to destroy a few churches and Christians in revenge. Of course, the entire eastern portion of this Syrian area, that is, most of present day Iraq, belonged to the great Persian Empire throughout this period.

King Kobad, previously expelled by his own nobles, returned to the throne in 501 and waged the first war with Byzantium. But his previous friends, the Ephthalites, raided from the northeast and he had to sue for peace with the Christians before he could finally expel the Asian invaders from Persia in A.D. 513. The 2nd Byzantine-Persian War followed from 524 to 531 and at the end of that conflict Kobad's son, Chosroes I (or Khosru or Khosrau), became the greatest of the Persian kings. To insure his dynasty, like many another Asian monarch, he executed all of his brothers and their male offspring with one exception and included Mazdak and all of his followers. It was he who finally completely defeated the Ephthalites in central Asia in 557.

Pahlavi, the Indo-European language of Parthian Persia, was still in use and Zorastrianism was the official religion, with the God Ormuzd and the devil Ahriman. Chosroes' reign was tolerant, however, to Nestorian and other brands of Christians and to Jews. He actually helped the Nestorians to establish a library. The great Persian Medical School at Gondishapur also had a famous medical library containing works from Byzantium and perhaps some of Hippocrates' works came through here to the Arabic world. In this hey-day of the Persian Empire, the University of Judi-i-Shapur became the greatest intellectual center of the world, with teachers and scholars from all over Europe and Asia. Roads and villages were rebuilt and there was reform of the fiscal system and taxation methods. Many irrigation systems were completed and the famous metal-workers of Antioch, Syria were brought to Iran. (Ref. 15, 8)

After the Persians had driven to the Mediterranean coast and taken all of the Arabian peninsula, Byzantine allied with the Turks drifting down from the Eurasian border,- but they still could not defeat the Persians. At the end of the century, however, the Persian Empire became divided into four great satrapies: the east, comprised of Khosasan and Kerman; the west, including Iraq and Mesopotamia; the north, made up of Armenia and Azerbaijan; and the south, which contained Fars and Khuziasan. Wars continued on all borders until the end of the century.