Jaxartes: Greek name of a large river in Central Asia now known as Syrdar'ya.
The Syrdar'ya is formed west of the Pamir Mountains, in the Fergana valley, by the junction of the rivers Karadar'ya and Naryn, and flows through modern Kazakhstan, Tajikistan, and Uzbekistan to Lake Aral, in which it empties itself after having covered a distance of over 2200 km. It is one of the largest rivers of Central Asia, but rather shallow and therefore unfit for ships. Still, its waters can be used for irrigation.
The Jaxartes separated Sogdia (roughly modern Uzbekistan), the northernmost satrapy of the Achaemenid Empire from the Central Asian steppes, which were occupied by the Sacae. Several fortifications were situated on it, including Cyropolis (founded by Cyrus the Great) and Alexandria Eschatê (founded by Alexander the Great and probably identical to modern Khodzent.
In the summer of 329, the Jaxartes was the site of one of Alexander's most brilliant battles.