Siege of Constantinople ( 674 – 78 ) The First Arab Siege of Constantinople in 674 – 678 was a major conflict of the Arab – Byzantine Wars , and the first culmination of the Umayyad Caliphate ' s expansionist strategy towards the Byzantine Empire , led by Caliph Mu ' awiya I . Mu ' awiya , who had emerged in 661 as the ruler of the Muslim Arab empire following a civil war , renewed aggressive warfare against Byzantium after a lapse of some years and hoped to deliver a lethal blow by capturing the Byzantine capital , Constantinople . As reported by the Byzantine chronicler Theophanes the Confessor , the Arab attack was methodical : in 672 – 673 Arab fleets secured bases along the coasts of Asia Minor , and then proceeded to install a loose blockade around Constantinople . They used the peninsula of Cyzicus near the city as a base to spend the winter , and returned every spring to launch attacks against the city ' s fortifications . Finally , the Byzantines , under Emperor Constantine IV , managed to destroy the Arab navy using a new invention , the liquid incendiary substance known as Greek fire . The Arab land army in Asia Minor was also defeated by the Byzantines , forcing the Arabs to lift the siege . The Byzantine victory was of major importance for the survival of the Byzantine state , as the Arab threat receded for a time . A peace treaty was signed soon after , and following the outbreak of another Muslim civil war , the Byzantines even experienced a period of ascendancy over the Caliphate . The siege left several traces in the legends of the nascent Muslim world , although it is conflated with accounts of another expedition against the city a few years previously , led by the future Caliph Yazid I . As a result , the veracity of Theophanes ' s account has been questioned by recent scholarship , which places more emphasis on the Arabic and Syriac sources . Background . Following the disastrous Battle of Yarmouk in 636 , the Byzantine Empire withdrew the bulk of its remaining forces from the Levant into Asia Minor , which was shielded by the Taurus Mountains from the Muslim expansion . This left the field open for the warriors of the nascent Rashidun Caliphate to complete their conquest of Syria , with Egypt too falling shortly after . Muslim raids against the Cilician frontier zone and deep into Asia Minor began as early as 640 , and continued under the leadership of the Rashidun governor of Syria , Mu ' awiya . The energetic Mu ' awiya also spearheaded the development of a Muslim navy , which within a few years grew sufficiently strong to occupy Cyprus and raid as far as Kos , Rhodes and Crete in the Aegean Sea . Finally , the young Muslim navy scored a crushing victory over its Byzantine counterpart in the Battle of Phoenix in 655 . Following the murder of Caliph Uthman and the outbreak of the First Muslim Civil War , however , Arab attacks against Byzantium stopped . In 659 , Mu ' awiya even concluded a truce with Byzantium , including payment of tribute to the Empire . The peace lasted until the end of the Muslim civil war in 661 , from which Mu ' awiya and his clan emerged victorious , establishing the Umayyad Caliphate . From the next year , Muslim attacks recommenced , with pressure mounting as Muslim armies began wintering on Byzantine soil west of the Taurus range , maximizing the disruption caused to the Byzantine economy . These land expeditions were sometimes coupled with naval raids against the coasts of southern Asia Minor . In 668 , the Arabs sent aid to Saborios , the " strategos " of the Armeniacs , who had rebelled and proclaimed himself emperor . Arab troops under Fadhala ibn ' Ubayd arrived too late to assist Saborios , who had died after falling from his horse , and they spent the winter in the Hexapolis around Melitene awaiting reinforcements . In spring 669 , after receiving additional troops , Fadhala entered Asia Minor and advanced as far as Chalcedon , on the Asian shore of the Bosporus across from the Byzantine capital , Constantinople . The Arab attacks on Chalcedon were repelled , and the Arab army was decimated by famine and disease . Mu ' awiya dispatched another army , led by his son ( and future Caliph ) Yazid , to Fadhala ' s aid . Accounts of what followed differ . The Byzantine chronicler Theophanes the Confessor reports that the Arabs remained before Chalcedon for a while before returning to Syria , and that on their way they captured and garrisoned Amorium . This was the first time the Arabs tried to hold a captured fortress in the interior of Asia Minor beyond the campaigning season , and probably meant that the Arabs intended to return next year and use the town as their base , but Amorium was retaken by the Byzantines during the subsequent winter . The Arab sources on the other hand report that the Muslims crossed over into Europe and launched an unsuccessful attack on Constantinople itself , before returning to Syria . Given the lack of any mention of such an assault in Byzantine sources , it is most probable that the Arab chroniclers — taking account of Yazid ' s presence and the fact that Chalcedon is a suburb of Constantinople — " upgraded " the attack on Chalcedon to an attack on the Byzantine capital itself . Opening moves : the campaigns of 672 and 673 . The campaign of 669 clearly demonstrated to the Arabs the possibility of a direct strike at Constantinople , as well as the necessity of having a supply base in the region . This was found in the peninsula of Cyzicus on the southern shore of the Sea of Marmara , where a raiding fleet under Fadhala ibn ' Ubayd wintered in 670 or 671 . Mu ' awiya now began preparing his final assault on the Byzantine capital . In contrast to Yazid ' s expedition , Mu ' awiya intended to take a coastal route to Constantinople . The undertaking was not haphazard , but followed a careful , phased approach : first the Muslims had to secure strongpoints and bases along the coast , and then , with Cyzicus as a base , Constantinople would be blockaded by land and sea and cut off from its agrarian hinterland , on which it depended for its food supply . Accordingly , in 672 three great Muslim fleets were dispatched to secure the sea lanes and establish bases between Syria and the Aegean . Muhammad ibn Abdallah ' s fleet wintered at Smyrna , a fleet under a certain Qays ( perhaps Abdallah ibn Qays ) wintered in Lycia and Cilicia , and a third fleet , under Khalid , joined them later . According to the report of Theophanes , the Emperor Constantine IV ( r . 661 – 685 ) , upon learning of the Arab fleets ' approach , began equipping his own fleet for war . Constantine ' s armament included siphon - bearing ships intended for the deployment of a newly developed incendiary substance , Greek fire . In 673 , another Arab fleet , under Gunada ibn Abu Umayya , captured Tarsus in Cilicia , as well as Rhodes . The latter , located midway between Syria and Constantinople , was converted into a forward supply base and centre for Muslim naval raids . Its garrison of 12 , 000 men was regularly rotated back to Syria , a small fleet was attached to it for defence and raiding , and the Arabs even sowed wheat and brought along animals to graze on the island . The Byzantines attempted to obstruct the Arab plans with a naval attack on Egypt , but it was unsuccessful . Throughout this period , overland raids into Asia Minor continued , and the Arab troops wintered on Byzantine soil . Arab attacks and related expeditions in 674 – 678 . In 674 , the Arab fleet sailed from its bases in the eastern Aegean and entered the Sea of Marmara . According to the account of Theophanes , they landed on the Thracian shore near Hebdomon in April , and until September were engaged in constant clashes with the Byzantine troops . As the Byzantine chronicler reports , " Every day there was a military engagement from morning until evening , between the outworks of the Golden Gate and the Kyklobion , with thrust and counter - thrust " . Then the Arabs departed and made for Cyzicus , which they captured and converted into a fortified camp to spend the winter in . This set the pattern that continued throughout the siege : each spring , the Arabs crossed the Marmara and assaulted Constantinople , withdrawing to Cyzicus for the winter . In fact , the " siege " of Constantinople was a series of engagements around the city , which may even be stretched to include Yazid ' s 669 attack . It should also be noted that both Byzantine and Arab chroniclers record the siege as lasting for seven years instead of five . This can be reconciled either by including the opening campaigns of 672 – 673 , or by counting the years until the final withdrawal of the Arab troops from their forward bases , in 680 . The details of the clashes during the subsequent years around Constantinople are unclear , as Theophanes condenses the siege in his account of the first year , and the Arab chroniclers do not mention the siege at all but merely provide the names of leaders of unspecified expeditions into Byzantine territory . It is only known that Abdallah ibn Qays and Fadhala ibn ' Ubayd raided Crete and wintered there in 675 , while in the same year Malik ibn Abdallah led a raid into Asia Minor . The Arab historians Ibn Wadih and al - Tabari report that Yazid was dispatched by Mu ' awiya with reinforcements to Constantinople in 676 , and record that Abdallah ibn Qays led a campaign in 677 , whose target is unknown . At the same time , the Byzantines had to face a Slavic attack on Thessalonica and Lombard attacks in Italy . Finally , in autumn 677 or early 678 Constantine IV resolved to confront the Arab besiegers in a head - on engagement . His fleet , equipped with Greek fire , routed the Arab fleet . It is probable that the death of admiral Yazid ibn Shagara , reported by Arab chroniclers for 677 / 678 , is related to this defeat . At about the same time , the Muslim army in Asia Minor , under the command of Sufyan ibn ' Awf , was defeated by the Byzantine army under the generals Phloros , Petron and Cyprian , losing 30 , 000 men according to Theophanes . These defeats forced the Arabs to abandon the siege in 678 . On its way back to Syria , the Arab fleet was almost annihilated in a storm off Syllaion . Aftermath . The failure of the Arabs before Constantinople coincided with the increased activity of the Mardaites , a Christian group living in the mountains of Syria that resisted Muslim control and raided the lowlands . Faced with this new threat , and after the immense losses suffered against the Byzantines , Mu ' awiya began negotiations for a truce , with embassies exchanged between the two courts . These were drawn out until 679 , giving the Arabs time for a last raid into Asia Minor under ' Amr ibn Murra , perhaps intended to put pressure on the Byzantines . The peace treaty , of a nominal 30 - year duration , provided that the Caliph would pay an annual tribute of 3 , 000 " nomismata " , 50 horses and 50 slaves . The Arab garrisons were withdrawn from their bases on the Byzantine coastlands , including Rhodes , in 679 – 680 . Constantine IV used the peace to proceed against the mounting Bulgar menace in the Balkans , but his huge army , comprising all the available forces of the Empire , was decisively beaten , opening the way for the establishment of a Bulgar state in the northeastern Balkans . In the Muslim world , after the death of Mu ' awiya in 680 , the various forces of opposition within the Caliphate manifested themselves . The Caliphate ' s division during this Second Muslim Civil War allowed Byzantium to achieve not only peace , but also a position of predominance on its eastern frontier . Armenia and Caucasian Iberia reverted for a time to Byzantine control , and Cyprus became a condominium between Byzantium and the Caliphate . The peace lasted until Justinian II ( r . 685 – 695 and 705 – 711 ) broke it in 693 , with devastating consequences : the Byzantines were swiftly defeated , Justinian was deposed and a twenty - year period of anarchy followed . Muslim incursions intensified , leading to a second and last Arab attempt at conquering Constantinople in 717 – 718 . Importance and impact . Constantinople was the nerve centre of the Byzantine state . Had it fallen , the Empire ' s remaining provinces would have been unlikely to hold together , and would have become easy prey for the Arabs . At the same time , the failure of the Arab attack on Constantinople was a momentous event . It marked the culmination of Mu ' awiya ' s campaign of attrition , pursued steadily since 661 . Immense resources were poured into the undertaking , including the creation of a huge fleet . Its failure had similarly important repercussions , and represented a major blow to the Caliph ' s prestige . Conversely , Byzantine prestige reached new heights , especially in the West : Constantine IV received envoys from the Avars and the Balkan Slavs , bearing gifts and congratulations and acknowledging Byzantine supremacy . The subsequent peace also gave a much - needed respite from constant raiding to Asia Minor , and allowed the Byzantine state to recover its balance and consolidate itself following the cataclysmic changes of the past decades . Cultural impact . Later Arab sources dwell extensively on the events of Yazid ' s 669 expedition and supposed attack on Constantinople , including various mythical anecdotes , which are taken by modern scholarship to refer to the events of the 674 – 678 siege . Several important personalities of early Islam are mentioned as taking part , such as Ibn Abbas , Ibn Umar and Ibn al - Zubayr . The most prominent among them in later tradition is Abu Ayyub al - Ansari , one of the early companions ( " Ansari " ) and standard - bearer of Muhammad , who fell before the city walls during the siege and was buried there . According to Muslim tradition , Constantine IV threatened to destroy his tomb , but the Caliph warned that if he did so , the Christians under his rule would suffer . Thus the tomb was left in peace , and even became a site of veneration by the Byzantines , who prayed there in times of drought . The tomb was " rediscovered " after the Fall of Constantinople to the Ottoman Turks in 1453 by the dervish Sheikh Ak Shams al - Din , and Sultan Mehmed II ( r . 1444 – 1446 , 1451 – 1481 ) ordered the construction of a marble tomb and a mosque adjacent to it . It became a tradition that Ottoman sultans were girt with the Sword of Osman at the Eyüp mosque upon their accession . Today it remains one of the holiest Muslim shrines in Istanbul . Modern reassessment of the events . The narrative on the siege accepted by modern historians relies largely on Theophanes ' account , while the Arab and Syriac sources do not mention any siege , but rather individual campaigns , some of which reached as far as Constantinople ( the capture of an island named near the city is recorded for 673 / 674 , and Yazid ' s 676 expedition is also said to have reached Constantinople ) . The Syriac chroniclers also place the decisive battle and destruction of the Arab fleet by Greek fire in 674 , during an Arab expedition on the coasts of Lycia and Cilicia , rather than Constantinople . This was followed by the landing of Byzantine forces in Syria in 677 / 678 , which began the Mardaite uprising that threatened the Caliphate ' s grip on Syria enough to result in the peace agreement of 678 / 679 . Based on a re - evaluation of the original sources used by the medieval historians , the Oxford scholar James Howard - Johnston , in his acclaimed 2010 book " Witnesses to a World Crisis : Historians and Histories of the Middle East in the Seventh Century " , rejects the traditional interpretation of events , based on Theophanes , in favour of the Syriac chroniclers ' version . Howard - Johnston asserts that no siege actually took place , based not only on its absence in the eastern sources , but also on the logistical impossibility of such an undertaking for the duration reported . Instead , he believes that the reference to a siege was a later interpolation , influenced by the events of the second Arab siege of 717 – 718 , by an anonymous source used by Theophanes . According to Howard - Johnston , " The blockade of Constantinople in the 670s is a myth which has been allowed to mask the very real success achieved by the Byzantines in the last decade of Mu ' awiya ’ s caliphate , first by sea off Lycia and then on land , through an insurgency which , before long , aroused deep anxiety among the Arabs , conscious as they were that they had merely coated the Middle East with their power " .