668 Mohammedans advance to Chalcedon and hold Amorium for a short time. Assassination of Constans at Syracuse. His son Constantine (IV) Pogonatus succeeds.
669 Mohammedans invade Sicily and carry off 180,000 prisoners from Africa.
670 Foundation of Kairwan, near Carthage.
673-677 Mohammedans besiege Constantinople. The Romans use the newly invented Greek fire against them.
678 Peace concluded with the Mohammedans.
679 Bulgarian War and foundation of the Bulgarian kingdom.
681 Constantine deprives his brothers Heraclius and Tiberius of the imperial title. The troops of the Orient had demanded that they, too, should receive the crown, and thus the Trinity in heaven might be represented on earth.
685 Justinian II succeeds his father. The caliph and emperor make peace.
687 Transference of the Mardaites from Lebanon to Thrace and Asia Minor.
689-690 Successful expedition of Justinian against the Bulgarians and Slavs. The Greeks are forced to emigrate from Cyprus; two hundred thousand Slavs transported to Asia Minor.