Syr Darya River, one of the major rivers of Uzbekistan and Central Asia.   Oxus and Jaxartes - ancient names of Amu Darya and Syr Darya Rivers

One of the major rivers of Central Asia, it is formed in the Fergana Valley, by the junction of the Naryn and Kara Darya rivers, which rise in the Tian Shan mountains.
It flows through Tajikistan, then through Uzbekistan and Kazakhstan, past Kyzylorda, and into the northern basin of the Aral Sea.

Shallowness of Syr Darya makes it unfit for navigation, but its waters are used for irrigating the important cotton-growing areas along its course and for hydroelectric power.
The Syr Darya forms the northern and eastern limits of the Kyzyl Kum desert. Alexander the Great in his conquest of Persia reached the river 329 BC and may have founded the chief city on its course - Khudjand on the site of an older city.

The Oxus River was the name that the classical Greek geographers (such as Herodotus) used for the Amu Darya (Darya is Persian for "sea").

The other major river in the area - the Syr Darya, which roughly follows the border between Uzbekistan and Kazakhstan, was called the Jaxartes by the Greeks.

The area beyond the Oxus (from a European or Middle Eastern viewpoint) used to be called Transoxiana (meaning "beyond the Oxus") by the Greeks. Later on, it was referred to as Maworaunnahr (meaning "beyond the river") by the Arabs.