That such a depression actually occurred, and that it extended through several centuries, is certain. Nor is it possible that its only cause was Egyptian competition, for had it been so, an equilibrium would have been reached when the African exchanges had been adjusted, whereas a continuous decline of prices went on until long after the fall of the Western Empire. The only other possible explanation of the phenomenon is that a contraction of the currency began soon after the death of Augustus, and continued without much interruption down to Charlemagne. Between the fall of Carthage and the birth of Christ, the Romans plundered the richest portions of the world west of the Indus; in the second century, North Africa, Macedon, Spain, and parts of Greece and Asia Minor; in the first, Athens, Cappadocia, Syria, Gaul, and Egypt. These countries yielded an enormous mass of treasure, which was brought to Rome as spoil of war, but which was not fixed there by commercial exchanges, and which continually tended to flow back to the natural centres of trade. Therefore, when conquests ceased, the sources of new bullion dried up, and the quantity held in Italy diminished as the balance of trade grew more and more unfavourable. Under Augustus the precious metals were plenty and cheap, and the prices of commodities were correspondingly high; but a full generation had hardly passed before a dearth began to be felt, which manifested itself in a debasement of the coinage, the surest sign of an appreciation of the currency. Speaking generally, the manufactures and the more costly products of antiquity came from countries to the east of the Adriatic, while the West was mainly agricultural; and nothing is better established than that luxuries were dear under the Empire, and food cheap.[32] Therefore exchanges were unfavourable to the capital from the outset; the exports did not cover the imports, and each year a deficit had to be made good in specie.