4 – Leo III (717 – 741)
Also known as Leo the Isaurian, this future Byzantine emperor was born in Syria in approximately 685 although some sources suggest he was born up to 10 years earlier. One of his great achievements was to bring an end to the Twenty Years’ Anarchy, a period of severe instability in the empire. This era was marked by a succession of weak rulers, and in 717, Leo seized the throne from the weak and ineffectual Theodosius III.
Leo had used deception to take the crown. He managed to convince the invading Arabs that he would help subjugate the empire for them in return for their support in his attempt to become emperor. Once he was the ruler, Leo organized Constantinople against the invaders. The Arabs felt betrayed and angrily attacked the empire’s capital city. Leo’s skillful organization held the enemy at bay; Greek Fire was used to great effect and ultimately, the Arabs had to abandon their siege of Constantinople.
It didn’t take long for Leo to establish himself as the supreme ruler of the empire; a fact which was emphasized with his swift dismissal of a rebellion in Sicily. He also displayed diplomatic skill and married his son Constantine to a daughter of the Khagan of the Khazars; the result was a powerful military alliance. Leo cleverly maintained good relations with the Bulgarians in the north of the empire. This allowed him to focus on driving back the Arabs. A significant victory at Akroinos in 740 ended any immediate Arab threat in Asia Minor. Unfortunately for the Empire, Leo died from dropsy in 741.
Leo was an excellent soldier-emperor who often led his men into battle. He restructured the theme system to decrease the throne’s vulnerability. Previously, certain themes were so large that its leader could conceivably take the crown by force. There is some doubt over whether he established a complex system of social reforms and his policy of Iconoclasm angered a number of religious groups. However, Leo should be remembered for saving the Byzantine Empire from an Arab conquest; with a less able ruler, Constantinople may well have fallen.