616 Persian invasion of Egypt. 617 The Persians occupy Chalcedon. 622 Heraclius proceeds in person against the Persians, and gradually wins back the Persian conquests. 628 Heraclius reaches Ctesiphon but is unable to take it. Rebellion in Ctesiphon. Chosroes and most of his family are slain. His eldest son =Kavadh (Kobad) II=, or =Siroes=, is made king. He murders most of his brothers, and sues for peace from the Roman Empire. A terrible pestilence breaks out and Kobad dies. His infant son, =Ardashir III=, succeeds. He is the last male Sassanid. The throne is disputed by many claimants. Chosroes, a son of Kobad II, makes himself king in Khorasan, but is soon slain. 629 The holy cross is returned to Heraclius. The general Shahrbaraz is supported in a claim to the throne by Heraclius. He takes Ctesiphon. 630 Murder of Ardashir, followed by that of Shahrbaraz. =Boran= or =Puran=, a daughter of Chosroes II, takes the throne. She makes a treaty with Heraclius. 631 Boran succeeded by =Peroz (Peroses) II=, who rules but a short time; then =Azarmidokht=, sister of Boran, takes the throne. =Hormuz V=, grandson of Chosroes II, maintains a rule over a portion of the country for a short time. 632 Azarmidokht dethroned by Rustem, hereditary marshal of Khorasan. =Ferrukhzadh= reigns a short time in Ctesiphon. 632 or 633 =Yezdegerd III=, grandson of Chosroes II, is put forward by some of the nobles and crowned. Ferrukhzadh is slain and Yezdegerd acknowledged as sole king. He declines to accept the Mohammedan religion at invitation of Abu Bekr, and the Moslems invade Persia. 636 Persian defeat by the Moslems at Cadesia, or Kadisiya. 640 or 642 The “Victory of Victories” by the Arabs over the Persians at Nehavend. The last great Persian army is shattered. The nobles gradually yield to the Arab chiefs. Yezdegerd is driven from place to place, continually shorn of more and more power until he is murdered in 651, and Persia becomes part of the Mohammedan dominions. THE ARABS THE PRE-MOHAMMEDAN ERA Before the Mohammedan conquests, Arabia is divided into a number of local monarchies. In these we recognise two distinct origins. (1) Those ruled by a race of southern origin--the genuine or Kahtanee Arabs. Their monarchies form a rim around the wild and desert centre of the peninsula. (2) The centre of Arabia is occupied by nomadic races--the Mustareb Arabs, of northern origin, descendants of a mythical Adnan. THE KAHTANEE KINGDOMS (_ca._ 380 B.C.-634 A.D.)