) or Bactriāna
). A province of the Persian Empire, bounded on
the south by Mount Paropamisus, which separated it from Ariana; on the east by the northern
branch of the same range, which divided it from the Sacae; on the northeast by the Oxus, which
separated it from Sogdiana; and on the west by Margiana. It was included in the conquests of
Alexander, and formed a part of the kingdom of the Seleucidae until B.C. 255, when Theodotus,
its governor, revolted from Autiochus II., and founded the Greek kingdom of Bactria, which
lasted till B.C. 134 or 125, when it was overthrown by the Parthians.