Editing Constantine IV (section)

==Early career==
The eldest son of [[Constans II]] and [[Fausta (wife of Constans II)|Fausta]], daughter of patrician [[Valentinus (usurper)|Valentinus]],<ref>{{harvp|Kazhdan|1991|loc="Constans II", p. 496}}</ref> Constantine IV had been named a co-emperor with his father in 654, almost certainly in [[Easter]] (13 April).<ref name=PBW>''[[Prosopography of the Byzantine World|PBW]]'' "[https://www.degruyter.com/document/database/PMBZ/entry/PMBZ14851/html Konstantinos IV]".</ref> His year of birth is unknown,<ref name=do>{{harvp|Grierson|1968|pp=512–514}}</ref> but often given as {{circa}} 650.<ref name=odb>{{harvp|Kazhdan|1991|loc="Constantine IV", pp. 500–501}}</ref>{{efn|Probably on the basis that most co-emperors were crowned as children. [[Honorius (emperor)|Honorius]] (384) was 9 years old, [[Theodosius II]] (401) was 1 year old, [[Valentinian III]] (425) was 6 years old, [[Leo II (emperor)|Leo II]] (473) was 6 years old, [[Theodosius (son of Maurice)|Theodosius]] (590) was 7 years old, and [[Heraclius Constantine|Constantine III]] (613) was 1 year old. [[David Tiberius|Tiberius]] and [[Constans II]] (641), were both 11 years old.}} He became emperor in September 668, when news arrived at Constantinople that [[Constans II]] had been assassinated in [[Sicily (theme)|Sicily]].<ref name=mango/>
[[File:The_concession_of_privileges_mosaic.jpg|thumb|269x269px|Mosaic of Constantine IV with his family and imperial figures. The upper legend reads: {{Smallcaps|constantinus maior imperator - heraclii et tiberii imperator}}.{{efn|The mosaic must have been made shortly before Heraclius and Tiberius' deposition in 681. [[Justinian II]] (far left) is depicted as being slightly taller than them, but this is impossible given that he was at least a decade younger.}}]]
The first task before the new Emperor was the suppression of the military revolt in Sicily under [[Mezezius]] which had led to his father's death.<ref>{{harvp|Bury|1889|p=330}}</ref> Within seven months of his accession, Constantine IV had dealt with the insurgency with the support of [[Pope Vitalian]],<ref>{{harvp|Bury|1889|p=315}}</ref> but this success was overshadowed by troubles in the east.

As early as 668 the [[Caliph]] [[Muawiyah I]] received an invitation from [[Saborios]], the commander of the troops in [[Armenia]], to help overthrow the Emperor at Constantinople.<ref>{{harvp|Bury|1889|p=306}}</ref> He sent an army under his son [[Yazid I|Yazid]] against the [[Byzantine Empire]]. Yazid reached [[Chalcedon]] and took the important Byzantine center [[Amorium|Amorion]].<ref>{{harvp|Bury|1889|p=307}}</ref> While the city was quickly recovered, the [[Umayyad Caliphate|Arab]]s next attacked [[Carthage]] and Sicily in 669.<ref name="Bury, p. 310">{{harvp|Bury|1889|p=310}}</ref> In 670 the Arabs captured [[Cyzicus]] and set up a base from which to launch further attacks into the heart of the Empire.<ref name="harvp|Moore|1997">{{harvp|Moore|1997}}</ref> Their fleet captured [[Smyrna]] and other coastal cities in 672.<ref name="Norwich, p. 323">{{harvp|Norwich|1990|pp=323–324}}</ref> Also, in 672, the Arabs sent a large fleet to attack [[Constantinople]] by sea.<ref name="Norwich, p. 323"/> While Constantine was distracted by this, the [[Slavs]] [[Siege of Thessalonica (676–678)|laid siege]] to [[Thessalonica]].<ref name="harvp|Moore|1997"/>