The returns which were sent of every province or district, expressed the number of tributary subjects, and the amount of the public impositions.
The latter of these sums was divided by the former; and the estimate, that such a province contained so many capita, or heads of tribute; and that each head was rated at such a price, was universally received, not only in the popular, but even in the legal computation.

The value of a tributary head must have varied, according to many accidental, or at least fluctuating circumstances; but some knowledge has been preserved of a very curious fact, the more important, since it relates to one of the richest provinces of the Roman empire, and which now flourishes as the most splendid of the European kingdoms.

The rapacious ministers of Constantius had exhausted the wealth of Gaul, by exacting twenty-five pieces of gold for the annual tribute of every head.

The humane policy of his successor reduced the capitation to seven pieces.

A moderate proportion between these opposite extremes of extraordinary oppression and of transient indulgence, may therefore be fixed at sixteen pieces of gold, or about nine pounds sterling, the common standard, perhaps, of the impositions of Gaul.