After the transaction of this business, he advanced against Bactra and Bessus, reducing the Drangians and Gadrosians[493] to subjection on his march. He also reduced the Arachotians to subjection and appointed Menon viceroy over them. He then reached the Indians, who inhabit the land bordering on that of the Arachotians. All these nations he reached marching through deep snow and his soldiers experiencing scarcity of provisions and severe hardship. Learning that the Areians had again revolted, in consequence of Satibarzanes invading their land with 2,000 cavalry, which he had received from Bessus, he despatched against them Artabazus the Persian with Erigyius and Caranus two of the Companions, also ordering Phrataphernes, viceroy of the Parthians, to assist them in attacking the Areians. An obstinately contested battle then took place between the troops of Erigyius and Caranus and those of Satibarzanes; nor did the barbarians give way until Satibarzanes, encountering Erigyius, was struck in the face with a spear and killed. Then the barbarians gave way and fled with headlong speed. Meantime Alexander was leading his army towards Mount Caucasus,[494] where he founded a city and named it Alexandreia.[495] Having offered sacrifice here to the gods to whom it was his custom to sacrifice, he crossed Mount Caucasus, after appointing Proëxes, a Persian, viceroy over the land, and leaving Neiloxenus son of Satyrus, one of the Companions, with an army as superintendent. According to the account of Aristobulus, Mount Caucasus is as lofty as any in Asia, and most of it is bare, at any rate in that part where Alexander crossed it. This range of mountains stretches out so far that they say even that Mount Taurus, which forms the boundary of Cilicia and Pamphylia, springs from it, as do other great ranges which have been distinguished from the Caucasus by various names according to the position of each. Aristobulus says that in this part of the Caucasus nothing grew except terebinth trees and silphium;[496] notwithstanding which, it was inhabited by many people, and many sheep and oxen graze there; because sheep are very fond of silphium. For if a sheep smells it even from a distance, it runs to it and feeds upon the flower. They also dig up the root, which is devoured by the sheep. For this reason in Cyrene,[497] some drive their flocks as far as possible away from the places where their silphium is growing; others even enclose the place with a fence, so that even if the sheep should approach it they would not be able to get within the enclosure. For the silphium is very valuable to the Cyrenaeans.