Underlying ideas and realities

Constantinople took the diplomatic initiative in order to defend its own vital interests on itswestern flanks, especially in Italy. Over time both Franks andByzantines expanded their imperial reach, and their concerns converged or collided in other regions as well. Thus Charlemagne’s destruction of the Avars in central Europe opened a power vacuum into which the dynamic Bulgar realm expanded from its headquarters at Pliska some 300 kilometres north of Constantinople. Bulgaria’s Greek inscriptions and inhabitants make its Byzantine cultural cachet unmistakable, and it may have acted occasionally as an intermediary.53 Ninth-century Franks and Byzantines shared powerful and dangerous neighbours in the Bulgars. Wherever its political centre lay, the new Slavic society of the Moravians which sprang up between the destruction of the Avars and the Hungarians’ arrival would greatly concern the eastern Franks and allow Byzantium to cultivate yet another power situated to Bulgaria’s rear. Finally, tenth-century links between Byzantium and northern Europe were foreshadowed by the Scandinavians’ appearance on the Black Sea, a fact perhaps not unconnected with the new north-eastern axis of Byzantine shipping, and the coalescence of a ‘northern arc’ of traders, linking the Baltic to the Middle East. In 839 Emperor Theophilos sent with his ambassadors to Louis the Pious some mysterious newcomers called ‘Rhos’. Louis knew a Viking spy when he saw one and so informed his Byzantine colleague.54 A couple of years later, the Byzantine ambassador to the Franks and to the Venetians communicated with the Baltic trading emporium of Hedeby, if we may judge from the excavators’ recovery there of his seal. The idea that this may have been connected with his known mission to recruit warriors for Byzantium is not weakened by the recent discovery of a second seal in another Scandinavian trading settlement.55 Ideas as well as realities conditioned Byzantium’s approach to the west. Byzantines viewed Constantinople as the capital of the Roman empire, a unique historical entity established by God to foster the spread of Christianity. Various barbarians had occupied parts of the whole but the empire retained theoretical claim to territories which were, for the time being, not effectively administered. This attitude affected imperial ideas about Italy, for example in Constantine V’s pressure on Pippin the Short, king of the Franks (751–68) to restore the exarchate of Ravenna to Byzantine control. A second idea conditioned Byzantine policy and was linked with the first: just as the Roman empire was a unique historical entity, so its ruler, the basileus – the Greek word had come gradually to occupy the semantic zone of the Latin word imperator, triumphing officially by 629 – was God’s lieutenant on earth and incomparably superior to other terrestrial rulers (archontes) or kings (reges). A family hierarchy of powers projected onto foreign relations the conceptions that structured domestic society. The Roman emperor reigned supreme as the father of all other rulers, although the exception once made for the Persian shah was now extended to the caliph, who was reckoned worthy of fraternal status. This would give a particular edge to the Frankish imperial usurpation, as viewed from Constantinople.56 The means by which Constantinople sought to effect its aims ranged from carefully calibrated gifts to armed intervention. Religious cooperation or conversion, subsidising potential rivals and cultivating satellite powers as buffers worked as well as dangling prospects of marriage with the imperial family. A favourite tactic was to encourage hostile action by the enemies of Byzantium’s enemies.57 All these approaches featured in the diplomatic dialogue with the west. Geographically and historically, a fragmented Italy and its complicated local politics held the key to Byzantine dealings in the west. The Lombard principalities of the Po basin, Spoleto and Benevento pressed against the increasingly autonomous Byzantine coastal areas stretching from Ravenna to Naples via Rome. At the extreme south of the Italian boot, first Sicily and later Calabria and Apulia anchored Constantinople’s power in Italy. The loss of Rome to the barbarians – for this is how Constantinople viewed the papal alliance with the Franks – and Carolingian ascendancy in Italy inevitably intensified Byzantine interest in the new transalpine power, especially when the Arabs of Africa surged across the Mediterranean to assault Byzantine Sicily and southern Italy.58