In his Buildings, Procopius devotes more attention to Justinian’s fortifications than to his churches (even though archaeology is suggesting that many of these had been initiated by Anastasius). It is a reminder of an empire under continuous military pressure. After 540 the successes in Africa and Italy were overshadowed by the devastating attack by the Persians on Antioch (from which the second city of the empire never fully recovered), the ravaging of Thrace by Huns, Bulgars, and Slavs, and the mounting problems in the campaigns in Italy. Added to this was the first of recurring outbreaks of bubonic plague. It spread from Egypt through Syria and Asia Minor, reaching Constantinople in 542. One theory is that an enormous volcanic eruption at Krakatoa resulted in a deterioration in climate—tree-ring growth was exceptionally low in many parts of the world between 530 and 550—and so famine which left a population especially vulnerable to infection. Although it is difficult to spot the impact of the disease in the archaeological record, it is estimated that between a third and a half of the population died in the worst affected cities. The effect on the morale of the empire and the manpower it could provide must have been profound but the survivors appear to have bargained to exploit their scarcity. One imperial decree complains of workers demanding two to three times the customary wage.
There is some evidence that the campaigns in Italy faltered under the impact of the plague so it is all the more remarkable that in the 550s the empire took the initiative once more and with some success. A fifty-year peace with Persia, which confirmed Lazica under Byzantine control, was signed in 561 and fighting was finally concluded in the empire’s favour in Italy in the 550s. The most intractable border was the northern. A whole range of peoples, Bulgars, Avars, Slavs, pressed on the empire. Raids reached well into Greece and, on occasions, to the walls of Constantinople itself. This was the period when the cities of Greece went into permanent decline. Athens was raided by Slavs and Avars in 582 and the sites of ancient Sparta, Argos, and Corinth were abandoned while the inhabitants of Corinth sought refuge high up on Acrocorinth. The only effective way of dealing with such a range of peoples was to play one off against another, and from the 550s Byzantine diplomacy was employed to foster enmities between them. An Avar delegation was received in Constantinople in 557 for instance, and the Avars allied by treaty to the empire. They went on to subdue a mass of people north of the Danube borders, although they later returned to exact further subsidies from the empire.
Theodora had died in 548. Justinian was aged 66. Traditionally, the years that followed have been seen as ones in which he withdrew from public affairs and became preoccupied with religion. (The comparison has been made with Philip II of Spain toiling night after night in his office in the Escorial.) His outstanding ministers, John the Cappadocian and Tribonian, were both dead by 542, just at the time the plague struck. Certainly this was a period when Justinian became increasingly cocooned within religious ritual. The city became a backdrop to the colourful ceremonial that accompanied his every move around the city. Yet Justinian’s diplomatic manoeuvres in the north of the 550s suggest a man still in control of policy-making and foreign affairs.
Certainly so far as religious affairs were concerned there was no withdrawal. Justinian was determined to resolve the continuing disputes over the nature of Christ. The search for unity was hampered by Monophysitism, still strong in the eastern provinces of the empire. As early as the 530s Justinian had been trying to find a way of bringing back the moderate Monophysites into the orthodox church. His best hope seemed to be to launch a new condemnation of ‘Nestorianism’ (of the variety preached by the Church of the East), in the hope that he could rally the Mono-physites behind him. He picked out the so-called Three Chapters, texts written by three fifth-century bishops within which sympathy for Nestorianism might be detected. The bishops had, however, been specifically cleared of any heresy at the Council of Chalcedon in 451 and so any attempt to condemn them now would undermine the authority of that council.
This did not prevent Justinian from calling a new council to meet in Constantinople in 553 to revive the issue. The emperor browbeat the attending bishops into accepting his interpretations of the texts. The result of what Judith Herrin has called ‘a hollow triumph of political intrigue and imperial intervention’ was to deeply offend the western church, whose bishops believed that the decisions of the Council of Chalcedon should not be discarded at the whim of an emperor. A schism between the western (Catholic) and eastern (Orthodox) churches was one step nearer. The Monophysites failed to be reconciled and in fact proceeded with the development of their own hierarchy. A tragic casualty of the Council of 553 was the condemnation as a heretic of the greatest of the earliest Christian theologians, Origen, by those insensitive to his Platonism and rejection of hellfire. (See further the overview by Patrick Gray, ‘The Legacy of Chalcedon: Christological Problems and their Significance, chapter 9 in Michael Maas (ed.), The Cambridge Companion to the Age of Justinian, Cambridge, 2005.)