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
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