northeastern outpost of the Persian empire was known to the Greeks as Cyropolis, after the Persian emperor Cyrus the Great. By the time of the fall of Persia to Alexander the Great, Greek villages, language, and culture were therefore all common in this area. Hellenistic rule (329–160 BCE) The region of Ferghana was conquered by Alexander the Great in 329 BCE and became his most advanced base in Central Asia. He founded (probably by occupying and renaming Cyropolis) the fortified city of Alexandria Eschate (Lit. "Alexandria the Furthest") in the southwestern part of the Ferghana valley, on the southern bank of the river Syr Darya (ancient Jaxartes), at the location of the modern city of Khujand (also called Khozdent, formerly Leninabad), in the state of Tajikistan. Alexander built a 6 kilometer long brick wall around the city and, as similarly in the cases of the other cities he founded, had a garrison of his retired veterans and wounded settle there. The whole of Bactria, Transoxiana and the area of Ferghana remained under the control of the Hellenistic Seleucid Empire until 250 BCE. The region then wrested independence under the leadership of its Greek governors Diodotus of Bactria, to become the Greco-Bactrian Kingdom. Greco-Bactrian kingdom (250–160 BCE) The Greco-Bactrians held their territory, and according to the Greek historian Strabo even went beyond Alexandria Eschate and "extended their empire as far as the Serica and the Phryni" (Strabo XI.XI.I). There are indications that they may have led expeditions as far as Kashgar in Xinjiang, leading to the first known contacts between China and the West around 200 BC. Various statuettes and representations of Greek soldiers have been found north of the Tien Shan, and are today on display in the museum of Urumqi (Boardman). Around 160 BC, the area of Ferghana seems to have been invaded by Saka tribes (called the Sai-Wang by the Chinese). The Sai-Wang, originally settled in the Ili valley in the general area of Lake Issyk Kul, were retreating southward after having been dislodged by Yuezhi (who themselves were fleeing from the Xiongnu): The Sakas occupied the Greek territory of Dayuan, benefiting from the fact that the Greco-Bactrians were fully occupied with conflicts in India against the Indo-Greeks, and could hardly defend their northern provinces. According to W. W. Tarn, Saka rule The Saka rule of Dayuan possibly started in 160 BC. When the Chinese explorer Zhang Qian