637 Battle of Cadesia, or Kadisiya, and victory over the Persians. Omar captures Jerusalem, and follows it up by taking Aleppo and Antioch. 638 Mesopotamia is conquered by the Mohammedans, also Tarsus and Diar-Bekr. 639 Invasion of Egypt by Amru. 641 Battle of Nehavend, and great victory of the Mohammedans over the Persians. Most of the Persian nobility come to terms with the Mohammedans. Yezdegerd the king flees to a remote corner of the realm, where he holds a vestige of power until 651 or 652. Alexandria captured. 644 Death of Omar, succeeded by =Othman=, a weak ruler, who allows the power to fall into the hands of the Koreish nobility. 647 Invasion of Africa by Abdallah. Arabian victories, expelling the Romans. 649 Invasion of Cyprus. 650 Conquest of Aradus. 652 Conquest of Armenia. 654 Conquest of Rhodes. 655 Defeat of the emperor Constans by the Mohammedans in naval battle off Mt. Phœnix in Lycia. 656 Murder of Othman by a party in opposition to the growing worldliness of Islam. =Ali=, of the opposition, and son-in-law of Mohammed, succeeds. Battle of the Camel. Ali victorious over his opponents. Moawiyah, governor of Syria, heads the opponents of Ali, and incites them to revenge. 657 Ali invades northern Syria. Battle of Siffin. The theocratic faction rebels against Ali. 658 Decision of the umpires, Ali and Moawiyah; the latter wins. Peace made with the Byzantine Empire. Egypt conquered for Moawiyah. 660 Truce between Ali and Moawiyah, dividing the caliphate into the East and West divisions. 661 Kharejite conspiracy to murder Ali, Moawiyah, and Amru. The former alone falls. His son =Hassan= succeeds, but abdicates in favour of Moawiyah. THE OMAYYAD DYNASTY (661-750 A.D.) 661 =Moawiyah= at head of the reunited caliphate. The opposition to him is gradually reduced. The capital is removed to Damascus. 662-663 Great invasion of Asia Minor. Death of Amru. 668 Mohammedans advance to Chalcedon and hold Amorium for a short time. 669 Great invasion of Sicily. 670 Foundation of Kairwan. 673-677 The Mohammedans besiege Constantinople, and are finally driven off by means of Greek fire. 676 Yazid, son of Moawiyah, is appointed heir-apparent. Hereditary nomination becomes a precedent. 678 Thirty years’ peace made with Constantine IV of Constantinople. 680 Death of Moawiyah. =Yazid I= succeeds. The Ali faction refuse recognition. Hosein, son of Ali, and his company slain. 681 Abdallah ben Zobair proclaims himself caliph. 683 Rebellion and sack of Medina. The cause of Ibn Zobair grows. He maintains a rival court at Mecca, and rebuilds the Kaaba. 684 Death of Yazid. His weak son, =Moawiyah II=, reigns but a few months. =Merwan= elected to succeed.