120 THE ROMAN EMPIRE
First, providers of wheat for Rome. These were the main surplus-
producing areas of the West, namely, north Africa, Sicily and Sardinia, plus,
in the East, Egypt. A passage of Pliny shows that grain also came to Rome
from Gaul, the Chersonese, Cyprus and Spain. Pliny was not presenting a
list, and if he had been, it is not complete. But in any case, the burden was
shared unevenly among this latter group and the main suppliers.^21
The unevenness of the division becomes clear if we inquire into the status
of the grain coming to Rome. The group of main suppliers provided the tax-
grain (plus the bulk of the grain that came in through supplementary tax,
requisitioning and compulsory purchase), the single most important category.
The same group provided most of the rent- grain from public or imperial
estates. With a third category, rent- grain from the estates of the Roman elite
brought in for their private consumption and for distribution in or outside
the market, we move to some extent outside the band of main suppliers, to
wherever upper- class Romans had estates at no great travelling distance from
Rome: in addition to Sicily and north Africa, Spain, the old Gallic province,
and, importantly, Italy.^22 Finally, grain purchased from private suppliers,
some under contract to the government, could have come from anywhere,
wherever the shippers involved had contacts. We know that ‘the fi ve colleges
of marine shippers of Arles’ worked for the Roman supply system ( annona ),
though there is no proof that their cargoes inevitably originated in Gaul.^23
The task of supplying Rome was spread somewhat beyond the main surplus-
producing provinces through the agency of such companies.
Next, provinces that supplied the army. The bulk of army supplies were
local in origin. This means that the main burden fell on the northern and
north- western provinces. Taking as our yardstick the disposition of the
legions around AD 150, almost two- thirds of the army was concentrated in
this sector of the empire. The Danube-Balkan region by itself supported ten
legions of about 55,000 men and about 140 auxiliary units of about 80,000,
more than half of them cavalry – in short, not much less than two- fi fths of the
total army of the mid- second century, and requiring almost 50,000 tonnes of
wheat alone each year. The north- west also had a substantial military
presence, about 50,000 and 45,000 legionaries and auxiliaries in Britain and
Germany, respectively. North Gaul was a major supplier of the Rhine armies;
Britain and to some extent Gaul provided for the British army; while the
Danubian legions drew deeply on the resources of the Balkan provinces.^24
No major grain exporter to Rome had to put up with a large garrison
as well. Egypt in the mid- second century had two legions and perhaps
17 auxiliary units, about 20,000 men in all, and Africa Proconsularis with
Numidia about half as many in the same period.
The third category of province comprises those contributing money-
taxes, about half of which, very approximately, 400 million sesterces, went
to the army as pay, donatives and discharge payments.^25 Such provinces
were either without garrisons or only lightly garrisoned, and with the
addition of Italy, which did not pay the land tax, they furnished much of the