invaded
the province of Romagna, which had already assumed that distinctive
appellation; the Catholics of the Exarchate yielded without reluctance
to his civil and military power; and a foreign enemy was introduced for
the first time into the impregnable fortress of Ravenna. That city and
fortress were speedily recovered by the active diligence and maritime
forces of the Venetians; and those faithful subjects obeyed the
exhortation of Gregory himself, in separating the personal guilt of Leo
from the general cause of the Roman empire. [49] The Greeks were
less mindful of the service, than the Lombards of the injury: the two
nations, hostile in their faith, were reconciled in a dangerous and
unnatural alliance: the king and the exarch marched to the conquest of
Spoleto and Rome: the storm evaporated without effect, but the policy
of Liutprand alarmed Italy with a vexatious alternative of hostility and
truce. His successor Astolphus declared himself the equal enemy of the
emperor and the pope: Ravenna was subdued by force or treachery, [50]
and this final conquest extinguished the series of the exarchs, who had
reigned with a subordinate power since the time of Justinian and
the ruin of the Gothic kingdom. Rome was summoned to acknowledge the
victorious Lombard as her lawful sovereign; the annual tribute of a
piece of gold was fixed as the ransom of each citizen, and the sword of
destruction was unsheathed to exact the penalty of her disobedience. The
Romans hesitated; they entreated; they complained; and the threatening
Barbarians were checked by arms and negotiations, till the popes had
engaged the friendship of an ally and avenger beyond the Alps. [51]

[Footnote 47: See West's Dissertation on the Olympic Games, (Pindar.
vol. ii. p. 32-36, edition in 12mo.,) and the judicious reflections of
Polybius (tom. i. l. iv. p. 466, edit Gronov.)]

[Footnote 48: The speech of Gregory to the Lombard is finely composed
by Sigonius, (de Regno Italiae, l. iii. Opera, tom. ii. p. 173,) who
imitates the license and the spirit of Sallust or Livy.]

[Footnote 49: The Venetian historians, John Sagorninus, (Chron. Venet.
p. 13,) and the doge Andrew Dandolo, (Scriptores Rer. Ital. tom. xii. p.
135,) have preserved this epistle of Gregory. The loss and recovery of
Ravenna are mentioned by Paulus Diaconus, (de Gest. Langobard, l. vi.
c. 42, 54, in Script. Ital. tom. i. pars i. p. 506, 508;) but our
chronologists, Pagi, Muratori, &c., cannot