Dio Cassius: History of Rome, Book LIII.xxix.3-8., c. 220 CE For 23 B.C.: While this was going on, another and a new campaign had at once its beginning and its end. It was conducted by Aelius Gallus, the governor of Egypt, against the country called Arabia Felix, of which Sabos was king. At first Aelius encountered no one, yet he did not proceed without difficulty; for the desert, the sun, and the water (which had some peculiar nature), all caused his men great distress, so that the larger part of the army perished. The malady proved to be unlike any of the common complaints, but attacked the head and caused it to become parched, killing forthwith most of those who were attacked, but in the case of those who survived this stage it descended to the legs, skipping all the intervening parts of the body, and caused dire injury to them. There was no remedy for it except a mixture of olive-oil and wine, both taken as a drink and used as an ointment; and this remedy naturally lay within reach of only a few of them, since the country produces neither of these articles and the men had not prepared an abundant supply of them beforehand. In the midst of this trouble the barbarians also fell upon them. For hitherto they had been defeated whenever they joined battle, and had even been losing some places;. but now, with the disease as their ally, they not only won back their own possessions, but also drove the survivors of the expedition out of the country. These were the first of the Romans, and, I believe, the only ones, to traverse so much of this part of Arabia for the purpose of making war. . .