The eye of Justinian investigated every spot; and his cruel precautions might attract the war into some lonely vale, whose peaceful natives, connected by trade and marriage, were ignorant of national discord and the quarrels of princes.

Westward of the Euphrates, a sandy desert extends above six hundred miles to the Red Sea.

Nature had interposed a vacant solitude between the ambition of two rival empires; the Arabians, till Mahomet arose, were formidable only as robbers; and in the proud security of peace the fortifications of Syria were neglected on the most vulnerable side.
[Footnote 125: See Procopius, Persic.l.i.c.19.

The altar of national concern, of annual sacrifice and oaths, which Diocletian had created in the Isla of Elephantine, was demolished by Justinian with less policy than] [Footnote 126: Procopius de Edificiis, l.iii.c.7.Hist.

l.