[1] The expedition to Arabia Felix, of which an account is given by his friend Strabo,[2] as well as by Cassius Dio[3] and Pliny the Elder[4][5] turned out to be a complete failure.
When Aelius Gallus set out with his army, he trusted to the guidance of a Nabataean called Syllaeus, who deceived and misled him.
Thence, they passed through a wasteland called Ararenê, occupied by a nomadic people, and thence proceeded another fifty days until reaching Najran.
The burning heat of the sun, the bad water, and the want of every thing necessary to support life, produced a disease among the soldiers that was altogether unknown to the Romans, and destroyed the greater part of the army; so that the Arabs were not only not subdued, but succeeded in driving the Romans even from those parts of the country which they had previously possessed.
At this time, Aelius Gallus and his army had spent six months on their military campaign in Arabia, on account of his treacherous guide, while he effected his retreat in sixty days, obliged to return to Alexandria, having lost the greater part of his force.