the old Roman provinces of
Italy. A new grouping of territories was not only necessary but was
already forming itself under the pressure of the conquest and its
terror. The regions which had escaped the barbarians were drawing
together without any regard for the ancient provincial divisions and
were grouping themselves about the cities, where the resistance, such
as it was, was concentrating itself, and where the imperial
administration had taken refuge.

If we confine ourselves for the moment to Italy north of the
Apennines, we shall find that in the old province of Liguria the vicar
of the prefect of the praetorium had fled from Milan to Genoa, and
that about that city the debris of the old province was slowly
re-assembling itself. In Venetia we shall find that the governor had
departed to Grado, and about this town as a centre the eastern part of
the old province was gathered. The western part of that province, cut
off from its capital, attached itself by force of circumstances to
what remained of Aemilia and of Flaminia, whose neighbour she was, and
these fragments of the ancient provinces all together grouped
themselves about, or found their centre in, Ravenna, the capital of
Flaminia and the residence of the prefect of Italy.

In these new groupings the great pre-occupation and the supreme
interest are defence--the defence of civilisation against the
barbarian.

Now, it was to regulate this new state of affairs that the exarchate
was created; or rather the exarchate was the official acknowledgment
of a state of affairs that the disastrous invasion of the Lombards had
brought about. The new order was established at the end of the reign
of Justin II. (565-578) under a new and supreme official. Without
doing away with the prefect of Italy the emperor placed over him as
supreme head of the new administration the exarch[1] who was both the
military commander-in-chief and the governor-general of Italy; and,
since the chief need of Italy was defence, without entirely
suppressing the civil administration, he placed at the head of each of
the re-organised provinces a certain military officer--the duke.

[Footnote 1: For the discussion of the derivation of the title
"Exarch," _see_ Diehl, _op. cit_. pp. 15-16.]

The earliest document that remains to us in which we find definite
mention of the exarch is the famous letter, dated October 4, 584, of
pope Pelagius II. to the deacon Gregory, his nuncio in Constantinople.