Some time between c. 724 and 755, a series of distinct developments coalesced
to undermine the old assumptions which governed the church of
Rome’s thinking about the empire. They did so at about the time trans-
Mediterranean communications in general reached their lowest ebb and
direct overland travel had ceased. The precise chronology and relative
weight of each development is disputed, but the overall result is clear.
As Constantinople reorganised, it increased the tax burden on the lands
of the Roman church. The papal establishment resisted paying. Despite
imperial efforts to stabilise the Arab threat from the south, expanding
Lombard power menaced Rome and Ravenna ever more acutely, even as
pressing military threats closer to home kept Constantinople from shoring
up Italy’s defences. Leo III’s new doctrine of iconoclasm met papal opposition.
The imperial government responded to papal tax delinquency by
confiscating the papal properties in Sicily and Calabria; then or somewhat
later, the emperor transferred ecclesiastical jurisdiction over southern Italy
and Illyricum from Rome to the patriarch of Constantinople.71
According to their loyal biographers, the popes vociferously protested at
doctrinal and administrative measures of which they disapproved even as
they dutifully represented imperial power in security matters. Thus in 713
Pope Constantine intervened to quell a murderous riot against an official
who had accepted an appointment in the name of Emperor Philippikos
(711–13), whose orthodoxy the pope himself had challenged.72 Gregory II
(715–31) is supposed to have quashed an Italian plan to elect a rival emperor
to oppose Leo III’s iconoclasm and attack Constantinople, despite purported
Byzantine plots on his life.73 Pope Zacharias (741–52) intervened
twice with the Lombard kings to protect Ravenna. Despite recognising the
usurper Artabasdos (see above, p. 258), he even obtained the imperial estates
of Ninfa and Norma in Campania from Constantine V.74
To judge from the imperial largesse, papal opposition sounded louder
locally and beyond Byzantine borders than it did inside the Great Palace
in Constantinople. Nonetheless, the pope had held a local synod in 731 to
clarify his position against iconoclasm. Roman links with theGreek milieux
of Jerusalem, which were ardently defending icons from the safety of the
caliphate, and with monks fleeing from Constantinople, perhaps stiffened
papal attitudes. The emperors’ appropriations of papal patrimonies and
jurisdictionwere certainly not tailored to soften the papal stand on doctrine.
Doctrinal and administrative differences might have remained just that,
as they had in far more dramatic circumstances a hundred years earlier,
were it not for the inexorable Lombard threat. This pressure produced a
triangular relationship between Constantinople, Rome and whoever controlled
the Po valley, in which every rapprochement between two of the
partners might threaten the third. When Rome urged Constantinople to
check the Lombard threat, it nonetheless dreaded that Constantinople
might sacrifice Rome to accommodate the Lombards. So, too, when the
popes entered their alliance with the Franks, Constantinople attempted to
bind the Carolingian kings to Byzantium – to the popes’ detriment. Paradoxically,
when Rome seemed strictly subordinated, relations between the
Franks and Byzantines were on the best footing, for instance immediately
after Pope Leo III’s restoration by Frankish arms in 799.
In its last century of existence, the Lombard kingdom centred on Pavia
must have had fairly intensive contacts with Byzantium, not least because
of its ongoing absorption of the exarchate of Ravenna. But records are rare.
Diplomatic exchanges, for instance, are known only in so far as the papacy
was involved. The extent of contacts is suggested by a few hints: a Byzantine
jester named Gregory entertained the court of King Liutprand (712–44);
Lombard royal charters emulated Byzantine models; and in 750, King Aistulf
forbade business with the Byzantines during periods of conflict.75
The same pope who convened the council condemning iconoclasm in
731 had secretly invited the Franks to attack the Lombards in what was,
after all, only a classic manoeuvre of Byzantine diplomacy. In 732, a Roman
council very publicly ignored imperial sovereignty. A decade or two after
the fact, a member of the Carolingian family remembered that the pope had
promised to defect from Byzantium if Charles Martel helped him. True or
not, it shows that under Pippin the Short the Carolingian clan fully grasped
the Byzantine implications of intervening in Italy.76
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