AORNOS, SIEGE OF (326 B.c.). Two natural fortresses bearing the name of Aornos are mentioned in the campaigns of Alexander the Great. One has been identified as Tashkurgan, and the other as Pir-sar north of the Buner river. The name is a corruption of the Sanskrit avarana which means "enclosure," or "fortress"; the Greeks interpreting this word by sound as meaning "the place to which no bird can rise." The Aornos at Pir-sar was a natural stronghold with a flat summit consisting of arable ground and containing a supply of water. Alexander attempted to take it by occupying a ridge overlooking it and separated from it by a ravine. Failing, he constructed a mound from the moun tain side to a small hill on a level with Aornos. The tribesmen took alarm and suggested a truce over the terms of which they argued, as their plan was to gain sufficient time to evacuate the rock secretly. Alexander discovering their intention allowed them to begin their retirement, then he fell upon them, slaughtered a large number and captured the stronghold. (J. F. C. F.) BIBLIOGRAPHY.-Arrian, Anabasis of Alexander; Diodorus Siculus; Bibliography.-Arrian, Anabasis of Alexander; Diodorus Siculus; G. Grote, History of Greece (1906) ; M. A. Stein, Alexander the Great The Times, Oct. 25 and 26 (1926) ; The Cambridge Ancient History, vol. vi. (1927).