It appears, however, that at least two exceptions were made to the general principle thus magniloquently asserted.

Julian had taken into his service, ere he quitted Europe, a strong body of Gothic auxiliaries; and, while at Antioch, he sent to the Saracens, reminding them of their promise to lend him troops, and calling upon them to fulfil it.

If the advance on Persia was to be made by the line of the Euphrates, an alliance with these agile sons of the desert was of first-rate importance, since the assistance which they could render as friends was considerable, and the injury which they could inflict as enemies was almost beyond calculation.

It is among the faults of Julian in this campaign that he did not set more store by the Saracen alliance, and make greater efforts to maintain it; we shall find that after a while he allowed the brave nomads to become disaffected, and to exchange their friendship with him for hostility.

Had he taken more care to attach them cordially to the side of Rome, it is quite possible that his expedition might have had a prosperous issue.
There was another ally, whose services Julian regarded himself as entitled not to request, but to command.