The Dayuan were the descendants of Greeks forcibly resettled in the area by the Persian Empire, as well as the subsequent Greek colonists that were settled by Alexander the Great in Ferghana in 329 BCE (see Alexandria Eschate), and had prospered within the Hellenistic realm of the Seleucids and Greco-Bactrians, until they were isolated by the migrations of the Yuezhi around 160 BCE and the Scythians in 140. It appears that the name "Yuan" was simply a transliteration of Sanskrit "Yavana" or Pali "Yona", used throughout antiquity in Asia to designate Greeks ("Ionians"), so that Dayuan would mean "Great Ionians" or "Great Greeks".