Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
Brittany was in Caesar's time
a country poor in corn. In the north-east dense forests, attaching
themselves to the heart of the Ardennes, stretched almost without
interruption from the German Ocean to the Rhine; and on the plains
of Flanders and Lorraine, now so fertile, the Menapian and Treverian
herdsman then fed his half-wild swine in the impenetrable oak-forest.
Just as in the valley of the Po the Romans made the production
of wool and the culture of corn supersede the Celtic feeding
of pigs on acorns, so the rearing of sheep and the agriculture
in the plains of the Scheldt and the Maas are traceable
to their influence.
In Britain even the threshing of corn
was not yet usual; and in its more northern districts agriculture
was not practised, and the rearing of cattle was the only known mode
of turning the soil to account. The culture of the olive and vine,
which yielded rich produce to the Massiliots, was not yet prosecuted
beyond the Cevennes in the time of Caesar.
