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".