Basil II died in December 1025 after a reign of almost fifty years. He left Byzantium the dominant power of the Balkans and Middle East, with apparently secure frontiers along the Danube, in the Armenian highlands and beyond the Euphrates. Fifty years later Byzantium was struggling for its existence. All its frontiers were breached. Its Anatolian heartland was being settled by Turkish nomads; its Danubian provinces were occupied by another nomad people, the Pechenegs; while its southern Italian bridgehead was swept away by Norman adventurers. It was an astonishing reversal of fortunes. Almost as astonishing was the recovery that the Byzantine empire then made under Alexios I Komnenos (1081–1118). These were years of political turmoil, financial crisis and social upheaval, but it was also a time of cultural and intellectual innovation and achievement. The monastery churches of Nea Moni, on the island of Chios, of Hosios Loukas, near Delphi, and of Daphni, on the outskirts of Athens, were built and decorated in this period. They provide a glimmer of grander monuments built in Constantinople in the eleventh century, which have not survived: such as the Peribleptos and St George of the Mangana. The miniatures of the Theodore Psalter of 1066 are not only beautifully executed but are also a reminder that eleventh-century Constantinople saw a powerful movement for monastic renewal. This counterbalanced but did not necessarily contradict a growing interest in classical education. The leading figure was Michael Psellos. He injected new life into the practice of rhetoric and in his hands the writing of history took on a new shape and purpose; he claimed with some exaggeration to have revived the study of philosophy single-handed. However, his interest in philosophy was mainly rhetorical and it was left to his pupil John Italos to apply philosophy to theology and to reopen debate on some of the fundamentals of Christian dogma. Modern historiography has singled out the period from 1025 to 1118 as the watershed of Byzantine history. George Ostrogorsky provided the classic interpretation.1 He saw the eleventh century as the beginning of Byzantium’s inexorable decline, which he attributed to the triumph of feudalism. Private interest gained at the expense of the state. Without effective central institutions it was impossible to mobilise the resources of the empire or provide any clear direction. Symptomatic of the decline of central authority was the struggle for power between the civil and military aristocracies. The latter emerged victorious with the accession to the throne of Alexios I Komnenos. But his success was limited and his restoration of the empire superficial, because ‘the empire was internally played out’. Ostrogorsky meant by this that the peasantry and their property were coming increasingly under the control of great landowners. He believed that this compromised the economic and demographic potential of the empire. Ostrogorsky’s presentation of the history of the Byzantine empire in the eleventh century has been attacked from two main directions. Paul Lemerle doubted that the eleventh century was a period of absolute decline at Byzantium.2 There is too much evidence of economic growth and cultural vitality, which he connects with ‘le gouvernement des philosophes’. The tragedy was Alexios I Komnenos’ seizure of power, which substituted family rule for the state. Robert Browning would add that Alexios damped down the intellectual and religious ferment of the eleventh century through deliberate use of heresy trials.3 Alexander Kazhdan takes a rather different view.4 He agrees that in the eleventh century Byzantium prospered.He attributes the political weakness of the empire to reactionary elements holding back the process of ‘feudalisation’. Alan Harvey presses this approach to extremes.5 He insists that the advance of the great estate was essential for economic and demographic growth. Kazhdan is also struck by the buoyancy and innovation of Byzantine culture. He connects this with a growth of individualism and personal relations. It was a victory for progressive elements, which were promoted rather than hindered by the Komnenian regime.6 Such a bald presentation does not do justice to the subtleties and hesitations displayed by the different historians nor to their skilful deployment of the evidence. It makes their views far more schematic than they are, but it highlights differences of approach and isolates the major problems. They hinge on the effectiveness of the state.Was this being undermined by social, economic and political developments? Though their chronology is differentOstrogorsky and Lemerle are both agreed that it was. They assume that the health of Byzantium depended on the centralisation of power. By way of contrast Kazhdan believes that imperial authority could be rebuilt on a different basis and this is what Alexios Komnenos was able to do. The nature of Alexios’ achievement becomes the key issue. A weakness of all these readings of Byzantium’s ‘eleventh-century crisis’7 is a willingness to take Basil II’s (976–1025) achievement at face value; to see his reign as representing an ideal state of affairs. They forget that his iron rule represents an aberration in the exercise of imperial authority at Byzantium. His complete ascendancy was without precedent. In a series of civil wars in the early part of his reign he destroyed the power of the great Anatolian families, such as Phokas and Skleros, but only thanks to foreign aid.He used his power to straitjacket Byzantine society and subordinate it to his authority. To this end he reissued and extended the agrarian legislation of his forebears. Its purpose was ostensibly to protect peasant property from the ‘powerful’ as they were called. It was, in practice, less a matter of the imperial government’s professed concern for thewell-being of the peasantry, more a way of assuring its tax revenues. These depended on the integrity of the village community which was the basic tax unit. This was threatened as more and more peasant property passed into the hands of the ‘powerful’. Basil II followed up this measure by making the latter responsible for any arrears of taxation which had till then been borne largely by the peasantry. Control of the peasantry was vital if Basil II was to keep the empire on a war footing, while keeping the empire on a war footing was a justification for autocracy. The long war he waged against the Bulgarians only finally came to an end in 1018 (see above, pp. 526–9). It exploited the energies of the military families of Anatolia and cowed the aristocracy of the Greek lands. They were terrified that they would be accused of cooperating with the Bulgarians. The war with the Bulgarians was bloody and exhausting, but it was a matter of recovering lost ground, not of gaining new territory. The Bulgarian lands had been annexed by John I Tzimiskes (969–76) in the aftermath of his victory over the Rus in 971. It was only the civil wars at the beginning of Basil II’s reign and the emperor’s own ineptitude that allowed the Bulgarians to recover their independence. Basil II’s triumph over the Bulgarians gave a false impression of the strength of the empire. In part, it depended on an absence of external enemies. Islam was for the time being a spent force; thanks to Byzantium’s clients, the Pechenegs, conditions on the steppes were stable; the Armenians were divided; and western Christendom was still bedazzled by Byzantium. The Rus officially converted to orthodoxy c. 988. This confirmed their passage into the Byzantine orbit. The Rus were essential to Byzantine greatness under Basil II. They provided Byzantium with soldiers and sailors, and their merchants made Constantinople the entrepot for the products of the Russian steppes and forests and stimulated its commercial role.8 This was complemented by the growing presence of Venetian merchants at Constantinople. In 992 Basil II encouraged their activities by reducing the tolls on their ships paid for passage through the Hellespont to Constantinople. The effect was to favour Constantinople’s role as the clearing house of Mediterranean trade and to underline her position as the cross-roads of the medieval world. Constantinople was, however, disproportionately large and gave a false impression of Byzantine strength. It drew its wealth and population from well beyond the political frontiers of the Byzantine empire. Under different circumstances this might leave it vulnerable. If forced to rely entirely on its own demographic and economic resources, Byzantium would have been condemned to the role of a regional power, at best. But it did not have to do so. The Armenian highlands were always an important recruiting ground for the Byzantine armies, but it went further than this. The Byzantine conquests in the east were followed under Byzantine auspices by Armenian colonisation of Cilicia, the Euphrates provinces and northern Syria. The Rus provided another recruiting ground. Basil II relied heavily on the Varangian guard, which not only formed an elite corps but was also an instrument of his political ascendancy. Reliance on foreigners was a double-edged sword. In the course of the eleventh century relations with the Armenians deteriorated, while those with the Rus began to cool. In 1043 for reasons that remain obscure Iaroslav the Wise, prince of Kiev, sent an expedition against Constantinople. It was easily defeated, but thereafter the Rus played a less prominent role in the affairs of the Byzantine empire. In due course, the Varangian guard would be recruited not from the Rus and Scandinavians but from exiled Anglo-Saxons. When pondering the collapse of the Byzantine empire in the eleventh century, it must be remembered that Basil II left his successors a poisoned legacy. The empire’s apparent strength depended on circumstances beyond its control. Conditions along its frontiers might change radically. Basil II’s policy of annexing Bulgaria and Armenia suited his own time, but would produce real difficulties for his successors. His greatest failure, however, lay elsewhere: he neglected to make adequate provision for his succession, and there would be no settled succession to the Byzantine throne for some seventy years until Alexios I Komnenos was securely in control.