The century began with Maurice (582–602) on the imperial throne, urging his army to resist the incursion of Slavs who were seeking to cross the Danube from the north bank. Growing discontent culminated in mutiny when Maurice ordered the army to continue their campaign against the Slavs into the winter months, when bare trees would provide less cover for the marauders. Led by Phocas, a relatively minor officer, the army marched on Constantinople and deposedMaurice. Phocas was proclaimed emperor, but was never very secure and faced a number of revolts. More seriously the Persian shah Khusro II (590–628) used Maurice’s murder as a pretext to declare war on the empire, to avenge his former protector (see above, pp. 127, 128).With the invasion of Syria, there began a war that would last until 626–7. In 610 Phocas was deposed by Heraclius, son of the exarch of Carthage, who, according to Theophanes, seized the throne at the invitation of the senate in Constantinople. Heraclius’ ships displayed reliquaries and icons of the Mother of God on their masts: a sign of the continuing authentication of political authority by supernatural means seen in the later decades of the sixth century. Phocas was swiftly overthrown and executed, and Heraclius acclaimed as emperor and crowned by the patriarch in St Stephen’s chapel in the palace. On the same day he married his betrothed, Eudocia, whom he crowned augusta. The situation Heraclius faced was grim. The Persians were now advancing into AsiaMinor, taking Caesarea in Cappadocia in 611, and to the north from across the Danube the Avars were once again a serious menace: in 615 both enemies would make a joint assault on Constantinople. Attempts were made to negotiate a peace treaty with the Persians – immediately, according to the eastern sources; according to the Greek sources, in 615, once the Persian forces had advanced as far as Chalcedon. Anyway the peace efforts were repudiated, as the Persians were convinced that the Byzantine empire lay at their mercy. The war took on the character of a holy war between a Christian army, using icons of Christ and the Virgin as banners, and the predominantly Zoroastrian army of the Persians. Besides advancing into Asia Minor, the Persians invaded Palestine, taking Jerusalem in early May 614, and then Egypt and Libya. The fall of Jerusalem, by now regarded by Christians as their Holy City, was a catastrophe for Byzantium as a Christian empire, and for the emperor as God’s vicegerent on earth. Still worse was the seizure of the relic of the True Cross, which was taken back to the Persian capital, Ctesiphon, along with Zacharias, patriarch of Jerusalem, and those Christian notables who survived the sack of the city; tens of thousands are said to have been killed.7 It was not until Heraclius had managed to negotiate a truce with the Avars that he was able to make a serious attempt to defeat the Persians. From 622 onwards he conducted a series of campaigns against them. In 626, while Heraclius was on campaign, the Persians joined forces with the Avars to besiege Constantinople. Heraclius himself did not return, but sent a contingent of the field army to reinforce the City’s defenders, who were under the leadership of the two regents, Patriarch Sergius and the magister officiorum, Bonus. Constantinople was besieged for ten days by a huge army of various peoples under the command of the khagan of the Avars, while the Persian army under Shahrvaraz held the Asian shore of the Bosporus. The siege failed when the fleet of Slav boats was destroyed by the Byzantine fleet in the Golden Horn, just across from the Church of the Virgin at Blachernae. The success of the Constantinopolitans’ defence of their city was ascribed to the Virgin Mother of God, and it is likely that the famous troparion ‘To you, champion commander’ was composed by Patriarch Sergius to celebrate her victory. Heraclius pressed his attack into the Sasanians’ heartland. The Persians were demoralised by their troops’ failure under Shahrvaraz to secure the City; they were also smarting at the destruction by the emperor’s brother Theodore of another contingent destined for Constantinople. Heraclius’ successes provoked a palace revolt in which Khusro was murdered, and the Persians sued for peace. All the territory they had taken was restored to the Byzantine empire, and the Tigris–Euphrates valley became the frontier once again.Heraclius recovered the True Cross, and celebrated his triumph by taking the relic on a tour of the restored Byzantine territories, before returning it to Jerusalem on 21 March 630.8 It would seem to be at this stage that Heraclius began to face the religious problems that had plagued the Byzantine empire since the council of Chalcedon in 451.9 The schism between those who supported Chalcedon and those who repudiated it, whom their enemies called monophysites, had become institutionalised with a separate monophysite episcopal hierarchy since the consecration of Jacob Baradaeus in 542. The monophysites had their greatest support in the eastern provinces, especially Syria and Egypt; many Christians in Armenia also declined to acknowledge the council of Chalcedon (see also below, pp. 333, 335). After conquering the eastern provinces, Khusro had sought to strengthen his hold over his new subjects by exploiting the Christians’ schisms. At a meeting held in Ctesiphon, Khusro met with leaders of the monophysites, the Armenians and also the Nestorians, the main Christian group established in Persia. These last had rejected the condemnation of Nestorius at the third ecumenical council of Ephesus in 431 and fled to Persia to escape persecution in the Byzantine empire. It was agreed that the Nestorians should retain their position within the traditional Sasanian territories, but that the Persian authorities would support the monophysites in Armenia and those former Byzantine provinces where the monophysites were in a majority, that is, Syria and Egypt. The monophysites welcomed this agreement, their patriarch of Antioch, Athanasius ‘the Camel Driver’, rejoicing at the ‘passing of the Chalcedonian night’. IfHeraclius was to be secure in his regained eastern provinces, he needed to gain the support of the monophysites. The policy he pursued was proposed by his patriarch Sergius, who had foreseen this problem and had already begun negotiations with monophysites: Sergius was himself Syrian, possibly with a monophysite background. The proposal was to seek union on the basis of the doctrine of monenergism, i.e. that Christ, while he had two natures, as Chalcedon had affirmed, possessed only a single divine-human activity. This policy achieved some success in Armenia, but the Syrian monophysites (Jacobites) were not amenable and required an explicit repudiation of Chalcedon. Monenergism’s greatest success was in Egypt, where Cyrus of Phasi, appointed patriarch and augustal prefect in 631, reached an agreement with the main monophysite group, the Theodosians. 10 On 3 June 633 a solemn eucharist celebrated the union with the Theodosians, on the basis of a carefully phrased pact of union in nine chapters; this placed monenergism in the context of the Cyrilline Chalcedonianism that had been espoused by Justinian and endorsed at the fifth ecumenical council in 553.11 But it was not only some of the monophysites who refused to accept monenergism. As Cyrus was about to celebrate his triumph of ecumenism, also present in Alexandria was the learned and highly respected abbot, Sophronius. To him, the nine chapters amounted to monophysitism. He protested to Cyrus, to no avail, and took his protest to Patriarch Sergius in Constantinople. Sergius was sufficiently alarmed by Sophronius’ protest to issue a ruling on the matter (the Psephos) in which he forbade any mention of either one or two activities in Christ. But that scarcely satisfied Sophronius, who took his complaint to Pope Honorius I in Rome. He seems to have had no success with the pope either, and from Rome he made his way to Palestine, where he was elected patriarch of Jerusalem in 634. In his synodical letter Sophronius exposed the heresy of monenergism, though without explicitly breaching the terms of the Psephos. Before Sophronius’ arrival in Constantinople, Sergius had already communicated the success of the doctrine of monenergism in Alexandria to Honorius, who in his reply used the phrase that was to lead to the refinement of monenergism into the doctrine of monothelitism. That phrase was ‘one will’.Monothelitism, the doctrine that Christ had only one divine will, was proclaimed as imperial orthodoxy in the Ekthesis issued by Heraclius in 638, although this was doubtless composed by Sergius. However, by 638 the immediate purpose of this religious compromise was being overtaken by events, for Heraclius’ triumph over the Persians proved a pyrrhic victory. Even while it was being celebrated, Palestine and Syria began to experience attacks from Arab tribes that within barely more than a decade would lead to the loss of the Byzantine empire’s eastern provinces – this time for ever – and the complete collapse of the Sasanian empire. In 633 there were Muslim attacks on garrisons in Gaza, and the Arab armies soon moved further north, although there is considerable confusion in the sources about the sequence of events thereafter.12 Heraclius mustered an army and sought to defeat the Arabs. The decisive battle took place at the river Yarmuk in 636, when the much larger Byzantine force was routed. Heraclius abandoned the eastern provinces in despair. The year before, Damascus had already fallen to the Muslims – or more probably had been surrendered – and in 638 Patriarch Sophronius surrendered Jerusalem to Caliph ‘Umar bin al-Khattab. Alexandria was taken in 642, and though the Byzantines recaptured it, in 645 it finally fell. By that time Mesopotamia had already fallen, and with it the Sasanian empire. The speed with which the eastern provinces of the Byzantine empire succumbed to the Arabs remains to be explained by historians. However attractive at first sight, the idea that these provinces, with their attachment to monophysitism, were already culturally lost to the empire does not seem to be borne out by the evidencewe have: on the contrary, there is much evidence for the continuing power of Hellenism in the eastern provinces well into the seventh century – evidence suggesting that Hellenic culture was more potent there than in the empire’s capital itself.13 When Heraclius died in 641, his death precipitated a dynastic struggle. He was succeeded by two of his sons: Constantine, by his first marriage to Eudocia; andHeraclius, known asHeracleonas, by his second wifeMartina, who was also his niece. Martina herself was given a special role to play as augusta.Heraclius’ marriage to his niece after the death of Eudocia had met with opposition at the time, and there was also opposition to the association of Martina as empress with the two emperors. Constantine’s death – the result of poisoning according to a rumour reported by Theophanes – only increased the opposition toMartina and Heracleonas; there were demands that the imperial dignity should be shared with Constantine’s son, also called Constantine, but usually known as Constans. As troops from the Anatolian armies appeared at Chalcedon in support of these demands, Heracleonas seems to have acceded to them. Nevertheless, Heracleonas and his mother were deposed and exiled, together withMartina’s other two sons, and Constans II became sole emperor. Constans inherited the continuing collapse of the eastern provinces to the Arabs: Egypt was slipping away and Muslim raids into Armenia began in 642–3. In 647 the future caliph Mu‘awiya (661–80) led a raiding party into Anatolia and besieged Caesarea, and fromthere they penetrated further still into Anatolia. The Arabs made no attempt to settle, but huge amounts of booty were taken back to Damascus.Mu‘awiya also realised the need for the Muslims to develop sea power, and in 649 he led a naval expedition against Cyprus, in which Constantia was taken. In 654 Rhodes was laid waste, Kos taken and Crete pillaged. The following year, in an attempt to remove the threat from the sea, the Byzantine fleet under the command of Constans himself engaged with the Arab fleet, but was defeated and Constans barely escaped with his life. The death of Caliph ‘Uthman in 656 precipitated a civil war (fitna) amongst the Arabs: one faction was led byMu‘awiya, proclaimed caliph in Syria, the other by ‘Ali, son-in-law of the prophet Muhammad. The civil war ended with the death of ‘Ali and the establishment of the Umayyad dynasty under Mu‘awiya in 661/2 – events provoking the schism in Islam between Sunni and Shiite that still endures. However, those years of civil war provided valuable respite for the Byzantines. Constans was able to turn his attention to the Balkans, where the power of the Avars had waned, and in 658 he led an expedition into the regions settled by the Slavs (Sklaviniai). There he met with considerable success, according to Theophanes, and was able to use the Slavs he captured to repopulate areas in Anatolia that had been devastated or depopulated. This policy of repopulating Anatolian regions by Slavs was to be continued by his successors, Constantine IV (668–85) and Justinian II (685–695/705–711). Constans also inherited his grandfather’s religious policy. By the early 640s, opposition to monothelitism had grown. Behind this opposition was the monk Maximus, known to later ages as ‘the Confessor’; he had been a close associate of Sophronius, who had originally stirred up opposition to monenergism.Maximus found support in Palestine and Cyprus, but more importantly in Italy and North Africa, where he had been in exile since the late 620s. These were areas which, in the sixth century, had protested against Justinian’s condemnation of the Three Chapters as compromising the decisions of Chalcedon.14 In North Africa a number of synods condemned monothelitism, and Maximus pressed home the attack in a series of skilfully argued tracts and letters. In 645 the former patriarch Pyrrhus arrived in North Africa; as a supporter of Empress Martina he had shared her fall. In July that year a disputation between the monothelite Pyrrhus and Maximus was held in Carthage, before the exarch Gregory, in which Pyrrhus admitted defeat and embraced orthodoxy.15 It was perhaps the strength of feeling against monothelitism that led Gregory to allow himself to be declared emperor in opposition to Constans in 646–7, but his rebellion was short-lived; he died the following year defending his province against Arab raiders. Meanwhile, Pyrrhus had made his way to Rome to declare his new-found orthodoxy to the pope, followed closely by Maximus. In 648, in a vain attempt to prevent further controversy, the famous Typos was issued in the name of the emperor by Patriarch Paul, forbidding discussion of the number of activities or wills in Christ. In Rome, Maximus prepared for a synod, together with other Greek monks who had fled west in the face of the Arabs or the heresy of the empire. This was finally held in 649 in the Lateran Palace in Rome, under the newly elected Pope Martin I (649–55): both the Ekthesis and the Typos were condemned, together with the patriarchs Sergius, Pyrrhus and Paul. The extent to which this synod was of Greek inspiration has become clear from recent research, which has shown that the Greek Acta of the synod are the original, the Latin version being a translation.16 Such open defiance of the imperial will could not be ignored. Olympius, exarch of Ravenna, was ordered to arrestMartin and compel the bishops gathered inRome to accept the Typos. When he arrived in Rome, Olympius discovered that, despite his best efforts, Pope Martin’s popularity made it hazardous to try and arrest him. In defiance of the imperial will he made his peace with Martin and departed for Sicily to deal with Arab raiders. There, like Gregory the exarch of North Africa, he may have been proclaimed emperor. But he died in 652. In the following year a new exarch arrived with troops and succeeded in arresting the pope. Martin was brought to Constantinople and tried for treason, with Olympius’ rebellion being cited as evidence. Although condemned to death, Martin’s sentence was commuted to exile and, already ailing, he was sent to Cherson in the Crimea, where he died in 655. Martin felt abandoned by those who should have supported him; his successor had been elected more than a year before his death. By that time,Maximus had already been arrested, likewise tried for treason and sent into exile in Thrace, where attempts were made to break his opposition to monothelitism. When that failed, he was brought back to Constantinople for trial. He was condemned as a heretic, mutilated and exiled to Lazica, where he soon died on 13 August 662. By the time Maximus died in exile, the emperor himself was in selfimposed exile from Constantinople. Around 662 Constans II and his court moved to Syracuse in Sicily. This attempt to abandon the beleaguered Constantinople and re-establish the court closer to the centre of the truncated empire recalls earlier plans by Heraclius, and shows that there was no sense that the Byzantine empire was now confined to the easternMediterranean. From his base in Sicily, Constans clearly intended to liberate Italy from the Lombards; before arriving at Syracuse, he had led a campaign in Italy. This had met with some success, though he failed to take Benevento and soon retired to Naples, from where he made a ceremonial visit to Rome. However, his residence in Sicily was extremely unpopular, imposing as it did an unwelcome financial burden on the island. There was also fierce opposition in Constantinople to the loss of the court, and in 668 Constans was assassinated by a chamberlain. Constans II was succeeded by his son Constantine IV. It was during Constantine’s reign that the Umayyad caliph Mu‘awiya made a serious attempt to complete the Arab expansion begun in the 630s, aiming to take Constantinople and with it destroy the only serious opposition to Muslim rule in theMediterranean. After his victory over ‘Ali in the fitna,Mu‘awiya renewed his offensive against the Byzantine empire. By 670 the islands of Cyprus, Rhodes and Kos, and the town of Kyzikos on the southern coast of the Sea of Marmara, had all been occupied by Arab naval forces. In 672 Smyrna was taken, and in 674 the main attack on Constantinople began. A large Muslim fleet blockaded the city, and for the next four years the same fleet was to blockade Constantinople, retiring in the winter to shelter off Kyzikos. Each year the defences of Constantinople held firm, and in the final naval battle, the Byzantines secured a major victory with the help of Greek fire. First mentioned in the sources on this occasion, Greek fire was a highly inflammable, crude oil-based liquid that was shot out at enemy ships, setting them ablaze.17 At the same time as this naval victory, the Byzantine army was able to surprise and defeat an Arab army contingent in Anatolia. Mu‘awiya was forced to break off his attack on Constantinople and sue for peace. This major victory for the Byzantines proved to be a turning point: the Arab threat to Constantinople receded for the time being and Byzantium’s prestige in the Balkans and the west was enhanced. Embassies from the khagan of the Avars, now restricted mainly to the Hungarian plain, and from the Balkan Slavs arrived in Constantinople, bringing gifts and acknowledging Byzantine supremacy. However, the situation in the Balkans was about to change. The Slavs based there had never formed any coherent political entity, though their presence confined imperial authority to Thessalonica and other coastal settlements. The Bulgars, a Turkic-speaking group whose homeland was to the north of the Sea of Azov, had long been a power among the nomadic peoples of the Eurasian steppes. The Byzantines had maintained friendly relations with them, and had supported them against theAvars.But with the arrival of another people – the Khazars – the Bulgars’ khanate began to split up, and one group led by Asparuch arrived at theDanube delta around 680, intending to settle south of the river in traditionally imperial territory. The Byzantines saw no threat in the Bulgars, but were unwilling to allow them south of theDanube.AByzantine fleet arrived at the river mouth and troops moved up fromThrace, intending to expel theBulgars. TheBulgars avoided open battle but, as theByzantine forces withdrew, took them by surprise and defeated them. Constantine IV concluded a treaty with Asparuch, granting theBulgars the territory they already held. As a result of this presence, several Slav tribes hitherto loyal to Byzantium recognised the overlordship of the Bulgars and became their tributaries, and a Bulgaro-Slav political structure started to develop, with its capital at Pliska. This independent, periodically hostile presence so close to the City, in principle able to control the route from the Danube delta to Constantinople, would prove a long-standing threat to the stability of the empire. The enforcement of monothelitism as imperial policy, though it secured papal acquiescence in the years immediately following Martin’s arrest and exile, was bound to prove ultimately unacceptable to the west, which saw the council of Chalcedon as endorsing the Latin Christology of Pope Leo I (440–61). By 680 Constantine had come to the conclusion that religious unity with the west was more important than the fragile possibility of union with the monophysites – now mostly lost to the Umayyad caliphate – offered by monothelitism. He proposed to Pope Agatho (678– 81) the calling of an ecumenical council to condemn monothelitism. Agatho enthusiastically concurred, and held synods in Italy and England to prepare for the coming ecumenical council. Armed with these synodical condemnations of monothelitism, the papal legates arrived in Constantinople. The sixth ecumenical council met in Constantinople from 3 November 680 until 16 September 681. Monenergism and monothelitism were condemned, and the patriarchs Sergius, Cyrus, Pyrrhus, Paul and Peter anathematised, together with Pope Honorius. There was no word, however, of the defenders of the orthodoxy vindicated by the council,Martin andMaximus, who had suffered at the hands of Constans; nor were the emperors Constans or Heraclius mentioned. Constantine IV himself was hailed, at the final session, as a ‘new Marcian’ and a ‘new Justinian’. The latter part of Constantine’s reign saw the Byzantine empire regain a certain stability. In 684–5 he led a successful military expedition into Cilicia, forcing Caliph ‘Abd al-Malik to sue for peace and pay tribute to the Byzantines (see below, pp. 344, 381–2). Religious reconciliation with Rome led to peace with the Lombards in Italy, brokered by the pope. In North Africa, the Byzantines were able to halt the advance of the Arabs through alliances with Berber tribes, though this only bought time until the Berbers themselves converted to Islam. Constantine IV died in 685 and was succeeded by his son, Justinian II. It is worth noting that both Constantine IV and Constans II had deposed their brothers in the course of their reigns – in Constantine’s case, despite open opposition from senate and army – in order to secure the succession of their eldest sons. Justinian sought to build on the relative stability achieved by his father, leading an expedition into the Balkans and reaching Thessalonica. He continued the policy of both his father and his grandfather of transporting Slavs into Anatolia. He also transported some of the population from Cyprus to Kyzikos, depopulated during the siege of Constantinople, and ferried Mardaites from northern Syria and Lebanon to the Peloponnese and elsewhere. Whether or not Justinian was responsible for the breach of the truce with ‘Abd al-Malik in 692, he suffered military disaster when his Slav troops deserted. As a result, several Armenian princes once again acknowledged Muslim suzerainty. In 692 Justinian called a council, known as the quinisext or fifth-sixth council (see below, pp. 244–7). In so doing, he followed both his father’s example and that of his namesake, declaring his credentials as emperor and guardian of orthodoxy. This was also manifest in his coinage: the image of the emperor was displaced from the obverse of the coin to the reverse, and replaced with an image of Christ, the source of his authority as emperor. In 695, Justinian was overthrown in a palace coup and replaced by Leontius (695–8), the recently appointed strat¯egos of the theme of Hellas. Justinian had his nose slit and was exiled to Cherson, where his grandfather had earlier exiled PopeMartin. Leontius’ reign lasted three years, during which he witnessed the end of Byzantine rule inNorth Africa. That defeat, and the consequent loss of Carthage, provoked another rebellion in which Leontius was deposed in favour of Apsimar, the droungarios of the Kibyrrhaiotai fleet, who changed his name to the more imperial-sounding Tiberius. Tiberius II reigned from 698 to 705, during which time Asia Minor was subjected to continual Arab raiding.He was replaced by Justinian II, who returned with the support of the Bulgar khan Tervel, slipping into the City through one of its aqueducts. Justinian’s final six years were ones of terror and vengeance, brought to an end by a military coup; thereupon three military leaders succeeded one another for short and inglorious reigns, until the accession in 717 of Leo III, the emperor who subsequently introduced iconoclasm.