Editing 717 (section)

==== Byzantine Empire ====
* [[March 25]] &ndash; Emperor [[Theodosios III]] is deposed after a reign of 1 year and 10 months. He is succeeded by the 32-year-old [[Leo III the Isaurian]], a general (''[[Strategos#Byzantine use|strategos]]'') of the [[Anatolic Theme]] (modern [[Turkey]]). Theodosios and his son enter the [[clergy]], and he probably becomes [[bishop]] of [[Metropolis of Ephesus|Ephesus]]. Leo brings an end to the [[Twenty Years' Anarchy]] in the [[Byzantine Empire]], which marks the beginning of the so-called [[Byzantine Empire under the Isaurian dynasty|Isaurian Dynasty]].<ref>Kaegi (1994), pp. 186, 195</ref><ref>Bellinger & Grierson (1992), p. 5</ref><ref>Jenkins, Romilly (1966). Byzantium: The Imperial centuries AD 610–1071, p. 56</ref>
* [[Arab–Byzantine wars#Attacks against Byzantine holdings in Africa, Sicily and the East|Arab–Byzantine War]]: Muslim general [[Maslama ibn Abd al-Malik]] leads his army of 80,000 men from [[Pergamon|Pergamum]] to [[Abydos (Hellespont)|Abydos]], where he crosses the [[Dardanelles|Hellespont]]. To prevent interference by the [[Bulgars]], or by any Byzantine forces in [[Thrace]], he sends part of his army to a covering position near [[Edirne|Adrianople]]; with his main body, Maslama builds [[Investment (military)|siege lines]] to blockade [[Constantinople]], which is protected by the massive [[Walls of Constantinople#Theodosian Walls|Theodosian Walls]].
* [[August 15]] &ndash; [[Siege of Constantinople (717–18)|Siege of Constantinople]]: Maslama begins a combined land and sea effort to capture Constantinople. The capital controls the [[Bosphorus|Bosporus]], access between the [[Mediterranean Sea|Mediterranean]] and [[Black Sea]], and is defended by a [[garrison]] of roughly 25,000 men. Leo III orders the [[Granary|granarie]]s be restocked and [[siege engine]]s installed. The Arab besiegers are suffering immense losses due to [[disease]], and from attrition of [[Siege|siege warfare]]. 
* [[September 1]] &ndash; A Muslim [[Naval fleet|armada]], consisting of 1,800 ships commanded by Admiral Suleiman, sails into the [[Sea of Marmara]] and drops anchor below the sea walls of Constantinople, to supply their forces ashore. Leo III orders the [[Byzantine navy|Byzantine fleet]] to sally forth from their protected [[harbor]]s with [[Greek fire]], setting alight the thickly-packed Muslim ships. Many vessels burst into flames, while others collide with each other before sinking.<ref>John Cairns, "Road to Manzikert" (2012). Byzantine Warfare in an Age of Crisis and Recovery (Chapter 3), p. 69. {{ISBN|978-1-84884-215-1}}</ref> 
* Fall &ndash; [[Basil Onomagoulos]], Byzantine official, declares himself rival emperor in [[Sicily]] after the news arrives that Constantinople has fallen to an Arab [[siege]]. Leo III dispatches a ''[[chartoularios]]'' named Paul, with imperial instructions for the Byzantine army on the island. Basil is arrested and executed; his head is sent to Leo, while the other rebels are [[Political mutilation in Byzantine culture|mutilated]] and [[exile]]d.