A large deduction must be allowed for the weakness of their enemies.

The birth of Mahomet was fortunately placed in the most degenerate and disorderly period of the Persians, the Romans, and the Barbarians of Europe: the empires of Trajan, or even of Constantine or Charlemagne, would have repelled the assault of the naked Saracens, and the torrent of fanaticism might have been obscurely lost in the sands of Arabia.
In the victorious days of the Roman republic, it had been the aim of the senate to confine their councils and legions to a single war, and completely to suppress a first enemy before they provoked the hostilities of a second.

These timid maxims of policy were disdained by the magnanimity or enthusiasm of the Arabian caliphs.

With the same vigor and success they invaded the successors of Augustus and those of Artaxerxes; and the rival monarchies at the same instant became the prey of an enemy whom they had been so long accustomed to despise.

In the ten years of the administration of Omar, the Saracens reduced to his obedience thirty-six thousand cities or castles, destroyed four thousand churches or temples of the unbelievers, and edified fourteen hundred moschs for the exercise of the religion of Mahomet.