In the spring of 327 BC Alexander the Great crossed the Indian Caucasus (Hindu Kush) and advanced to Nicaea, where Omphis, king of Taxila and other chiefs joined him. Alexander then dispatched part of his force through the valley of the Kabul River, while he himself advanced into Bajaur and Swat with his light troops. Craterus was ordered to fortify and repopulate Arigaion, probably in Bajaur, which its inhabitants had burnt and deserted. Having defeated the Aspasians, from whom he took 40,000 prisoners and 230,000 oxen, Alexander crossed the Gouraios (Panjkora) and entered the territory of the Assakenoi and laid siege to Massaga, which he took by storm. Ora and Bazira (possibly Bazar) soon fell. The people of Bazira fled to the rock Aornos, but Alexander made Embolima (possibly Amb) his base, and attacked the rock from there, which was captured after a desperate resistance. Meanwhile, Peukelaotis (in Hashtnagar, north-west of Peshawar) had submitted, and Nicanor, a Macedonian, was appointed satrap of the country west of the Indus.