the east to Wght the Parthian war and their return infected with
disease could well have spelled social and economic disaster.113 Raid-
ing was an alternative means of sur vival, and would have been made
easier by the depletion of the frontier garrisons. But, in the mid-160s,
raiding drew imperial attention and resulted in a build-up of imper-
ial forces clearly intent on aggression. No wonder that some Quadi
and Marcomanni panicked and attacked Wrst. And no wonder that
Roman forces, expecting relatively easy victory, were surprised and
let them through. The invasions of Italy and Greece should never
have happened. But the basic weakness of the Empire’s Germanic
enemies is shown in how quickly Rome was able to restore the
situation, and take the oVensive. Again, Rome was the aggressor
here: Marcus Aurelius was set on annexing new territories.114
The Wrst phase of the Marcomannic Wars, from 168–75, was
therefore not fought by an Empire on the defensive. The decisive
incident was the ‘invasion’ of Italy—humiliating in itself and raising
memories of the Cimbri, and even of Brennus. The second phase,
from 178–80, followed exactly the same pattern, as Marcus, obstin-
ately fulWlling his duty, returned to Wnish what had been interrupted
by revolt. Now, however, there was an additional, more conventional,
factor in play. The young (he was born in 161) Commodus’ formal
acceptance as heir had been accelerated to meet the challenge of
Avidius Cassius, and as part of this process he needed to be accepted
by the army. The second phase, like the Wrst, was characterized by
Roman aggression and military superiority.115 Birley describes the
conXict as ‘a grim and sordid necessity’; but it was necessary only
because Marcus regarded it as such. There appear to have been
numerous opportunities for a negotiated peace, but these he chose
to ignore.116 Again as in 16 bc, there was a ‘threat’ on the Danube in
the 170s but it was Roman, not Germanic.
Following Commodus’ departure from the northern frontier, there
was peace with the Germani for several decades. Even prolonged
Roman political instability and civil war, prompted by the assassin-
113 Burns (2003: 229–35); cf. below 49, n. 36.
114 Birley (1987: 142, 163, 183, 207, 209, 253); Isaac (1992: 390–1).
115 See Birley (1987: 207–9).
116 See, e.g. Birley (1987: 155–6, 169–70).
Prelude 31