Sogdiana (sŏgdēā´nə), part of the ancient Persian Empire in central Asia between the Oxus (Amu Darya) and Jaxartes (Syr Darya) rivers. Corresponding to the later emirate of Bukhara and region of Samarkand, it was also known as Transoxiana. Sogdiana, though often a possession of other countries, had its own language, culture, and trading centers. Ancient Sogdian was a Persian language written in an Aramaic script. Sogdiana was a satrapy under Darius I. Conquered 329 BC by Alexander the Great, it fell (7th cent. AD) to the Arabs and was a center of Islamic culture until 9th cent. Controlled (13th–15th cent.) by the Mongols, the region was later ruled by the Uzbeks and the emirs of Bukhara (see Bukhara, emirate of).