The eighth century was not only a time of obscurity, but also one of adversity, when man and nature conspired to bring the empire almost to the point of extinction. A series of natural catastrophes afflicted Constantinople and its hinterland in the middle of the century. An earthquake brought down the walls of the City on 26 October 740. The Justinianic plague (see above, p. 123; below, pp. 478–9) returned one last time; starting in Mesopotamia and travelling through Sicily and the Peloponnese, the epidemic reached the capital in 747, emptying the City of its inhabitants.6 The winter of 763–4 was so harsh that the Black Sea and the Sea of Marmara froze, with huge icebergs on the Bosporus threatening the City’s sea walls during the thaw. In 766, a drought affected Constantinople’s water supply.7 As if nature’s depredations were not enough, man brought incessant warfare to the empire. At the beginning of the eighth century the Arabs were waging a war of annihilation against the empire. Enormous Arab land and sea forces encircled Constantinople in 717, attempting unsuccessfully to seize it, and this operation was repeated atNicaea in 727.8 There followed almost ritualised warfare in Asia Minor, with annual raids by the caliph’s armies; although they seldom succeeded in capturing Byzantine cities, they ravaged the countryside and carried off the population and livestock. The Arabs could also mount both large-scale invasions – Harun al-Rashid’s expedition in 782 reached as far as Chrysopolis, opposite Constantinople9 – and sea raids, such as those launched on the Sicilian coast by ships from Ifriqya. The Isaurians managed to save the empire by raising an army which could go to the aid of besieged cities, but which was also capable of defeating enemy armies in open country, as it did at the battle of Akroinon in 740 (see below, p. 386).10 During the upheavals caused by the transition of power from the Umayyads to the Abbasids, the Byzantines took the offensive. They raided beyond the Taurus in 751 to Melitene and in either 754 or 755 to Theodosioupolis, transplanting these cities’ populations.11 The offensive also took place by sea. The fleet of the Kibyrrhaiotai destroyed an Arab fleet off Cyprus in 748;12 and the organisation of a Sicilian fleet during the 750s put paid to half a century of incessant Arab raiding on Sicily.13 Even after the empire had been saved from annihilation and a lasting border between the two empires had been drawn at the Taurus, warfare continued: but now it was waged by new enemies. On the Arab side, the annual raids in Asia Minor continued to ravage Cappadocia and were particularly dangerous when the empire was weak, or the caliphate in a strong position. Such was the case under Empress Irene (797–802) when, in 798, a detachment got as far as Malagina and stole a saddle from the imperial stables. And during the revolt of Thomas the Slav in 823, Thomas’ supporters allowed Arab raiders to reach Bithynia.14 Finally, there were two such emergencies under Theophilos: when Caliph al-Ma‘mun (813–33) led successful raids in person from 830 to 832, capturing Lulon and Tyana; and again in 838, when Caliph al-Mu’tasim (833–42) responded to the emperor’s attack on Sozopetra in Syria in the previous year, defeating him roundly at Dazimon and capturing Amorion, capital of the theme of the Anatolikoi and cradle of the ruling dynasty. In the 150 years of conflict, only two major truces were concluded – in 782 and 806; both imposed humiliating terms on the Byzantines, who had to pay tribute, and altogether they suspended the fighting for fewer than five years. The chain of signal-towers functioning by the ninth century, possibly even by the eighth, shows the permanent nature of the conflict with the caliphate. The towers ran from the northern entrance of the Cilician Gates, on the border at Lulon (near Ulukis¸la), to the Pharos of the imperial palace in Constantinople, and signals alerted the emperor to Arab incursions within the hour.15 But in the ninth century it was attacks by sea, independent of the caliphate, which did most harm. Euphemios, turmarch of Sicily, summoned the Aghlabids of Kairouan to help him in his rebellion against Michael II, and in 827 they landed and besieged Syracuse (see below, p. 462). Thus began the conquest of Sicily which was to drag on for the rest of the century. It was probably in this same year that Crete was attacked and soon taken by exiles from Cordoba; they had captured and subsequently been driven out of Alexandria by the caliph’s army.16 Crete and Sicily served as bases for raids on the islands and the Aegean littoral, now under constant threat; so, too, were the coasts of southern Italy, and Bari was captured around 842. On the northern border a new front was opened in 754 against the Bulgars in Thrace. Constantine V had made Thrace more secure through repeated campaigning in the last fifteen years of his reign, particularly with his victory at Anchialos in 763. On Constantine’s death, Thrace enjoyed a state of peace, with its network of kastra where garrisons were stationed17 and its renovated roads.18 This is illustrated by Empress Irene’s progress in 784 when she went as far as Beroia and Anchialos, which she ‘ordered to be rebuilt’.19 Relations with the Bulgars were in fact so close that in 776–7 Khan Telerig sought refuge in Constantinople, where he was baptised in the presence of Leo IV (775–80) and married one of Empress Irene’s relations.20 But under Irene and Constantine VI (780–97) the northern border became very dangerous once again. The Bulgars crushed the armies sent against them – as at Markellai in 792 – and their power increased still further under Khan Krum (c. 803–14). The efforts of Nikephoros I (802–11) to get the better of them ended in disaster in 811. The Bulgars annihilated the imperial army after it had seized their capital Pliska; Nikephoros was killed and his skull was used by Krum as a drinking goblet.21 This disaster was compounded two years later by the defeat at Bersinikia near Adrianople; the resulting fall of the Byzantine towns and fortresses of Beroia, Probaton, Anchialos and Mesembria allowed the Bulgars to devastate Thrace and Macedonia. The state of emergency which arose after Bersinikia led to the seizure of the throne by Leo ‘the Armenian’, strat¯egos of the theme of the Anatolikoi; he organised the defence of Constantinople, while the people assembled at Constantine V’s tomb, crying: ‘Arise and help the state which is perishing!’22 The death of Krum and the victory of Leo V in 816 changed the situation once again; a treaty was signed that same year and brought peace for more than three-quarters of a century, allowing for the reconstruction of the region.23 One portion of the empire which saw little warfare in this period was mainland Greece and the Peloponnese, following massive Slavonic immigration there in the seventh and eighth centuries; occasional Byzantine military expeditions were sufficient to ensure continued overlordship. Constantine V subjugated the Sklaviniai of Macedonia around 759;24 and in 783 Staurakios the eunuch, logothete of the Drome under Irene, led an expedition against the Sklaviniai inMacedonia (or Thessaly25), Greece and the Peloponnese, returning victorious with booty and captives. Although previously considered of great importance, this expedition has recently been re-evaluated so far as the Peloponnese is concerned, with archaeological and sigillographic records showing the claims of the so-called Chronicle ofMonemvasia to be exaggerated. According to the Chronicle, the Peloponnese had been abandoned to the Avaro-Slavs for 218 years – from the sixth year of the reign ofMaurice (582–602) to the fourth year of Nikephoros I’s reign – with the exception of the eastern part, from Corinth to CapeMalea, where the emperor sent a strat¯egos.26 In reality, the Slavs were never completely beyond imperial control in the eighth century. In Thessaly, the seals of Slav archontes27 attest imperial recognition, and even in the less politically organised Peloponnese, the Slavs came into contact with the Greek population, which was more numerous in the eastern part of the peninsula. This contact occurred not only at the level of military administration, as shown by seals of strat¯egoi and droungarioi found around Argos, but also of church administration, as shown by seals and the presence of bishops at the second council of Nicaea.28 Two revolts by the Slavs in the Peloponnese had to be put down by military force in the course of the ninth century. First came the rebellion of the Slavs of Patras in the reign of Nikephoros I, recounted by Constantine VII Porphyrogenitus (945–59); this eventually led to the appropriation of both them and their property by the archbishopric of Patras, which was then asserting its independence from Corinth. Secondly, in 842 the Melingoi and Erizites further to the south rose in revolt and, once suppressed, were subjected to tribute.29 War was not only caused by enemy attacks on the empire; imperial succession could also lead to bloody civil war. On the death of Leo III on 18 June 741, his son Constantine V had to put down a revolt led by his brother-in-law Artabasdos; Constantine was supported by the fleet of the Kibyrrhaiotai and the armies of the Anatolikoi and the Thrakesioi, while the Opsikion, Thrace and the Armeniakoi backed Artabasdos. In the summer of 742 Artabasdos was proclaimed emperor in Constantinople, which was then besieged and, on 2 November 744, captured by Constantine.30 Some eighty years later, Thomas the Slav, turmarch of the foideratoi in the Anatolikoi, rebelled againstMichael II on Christmas Eve 820;Michael was Leo V’s successor and was generally considered to have been responsible for his murder.31 The rebellion lasted three years and nearly succeeded, for Michael could only count on Constantinople and its fleet and the themes of Opsikion and the Armeniakoi, whereas Thomas controlled everything else, including the tax revenues, and had been crowned emperor at Antioch. Thomas laid siege to Constantinople in 821–2, but was foiled by a Bulgar attack andMichael’s destruction of his fleet using Greek fire. In the end he took refuge in Thrace, where he was captured by Michael at Arkadiopolis in October 823.32 The battle fought against the army of the Armeniakoi in 793 by Constantine VI at the head of all the other armies might also be considered a struggle for the succession. The Armeniakoi did not want Irene to be co-ruler with her son Constantine, who had been reconciled with her after a spell of sole rule (790–2). They wanted to remain loyal to him alone and to their strat¯egos Alexios Musele(m), who had been blinded for alleged complicity in a plot in favour of the caesar Nikephoros (son of Constantine V and uncle of the emperor) after the debacle at Markellai at the hands of the Bulgars in 792. Although this third civil war was apparently confined to the army, the other two, which both lasted over two years and involved sieges of the capital, also affected the civilian population. Thus, war dominated the eighth and early ninth centuries. Under the Isaurians it was a war of survival which overshadowed society as a whole and still threatened the empire’s very existence at the beginning of the ninth century, as can be seen from the Constantinopolitans’ reaction in 813 at the tomb of Constantine V. After 830, however, war affected mainly the armed forces in operations on the border with the caliphate, on the islands and in Italy; and even in these far-flung areas, its impact varied. Thrace, a land of reconquest and colonisation from 750, was ravaged by the enemy during the years 811 to 813, but regained its peace and prosperity after 816. Asia Minor suffered heavy but uneven losses. As the caliphs abandoned hopes of conquering the empire, a border gradually emerged between the Aegean and the Black Sea, along a line from Seleukeia to Trebizond; this became a sort of no-man’s-land, frequently changing hands, and studded with nineteen fortresses, according to Ibn Khurradadhbih.33 Regions close to the border were particularly exposed, such as Cappadocia and the Pamphylian and Lycian coasts; so too were the Anatolikoi, Armeniakoi and Opsikion, which bore the brunt of the Arab attacks. In contrast, the inhabitants of the Thrakesioi and the Black Sea coast were largely spared.34 The Kibyrrhaiotai successfully protected the Aegean islands in the eighth century, but after the Arab conquest of Crete in the 820s they became front-line targets. At the same time Sicily, after fifty years of peace following an earlier fifty years of raids, also came under attack. Finally, Constantinople itself was besieged four times, twice by foreign armies, in 717–18 and 813. It is difficult to determine the precise impact of both plague and continuous warfare on population figures; however, this was already being felt in the seventh century, and the population level seems to have reached its nadir in the eighth,35 although the situation was not uniform. Greece and the islands appear to have been more densely populated than the rest of the empire in the eighth century, but this changed after a century of Arab raiding. In Constantinople, the low point was the plague of 747–8; according to Patriarch Nikephoros, plague emptied the City of its inhabitants, and although it is difficult to give precise figures for the surviving population, estimates vary from 40,000 to 70,000.36 Constantinople was a case apart; while greatly affected by the plague, it also profited from war in demographic terms, thanks to the influx of refugees into the capital – a topic rarely studied.