Many history buffs and others less interested in history often wonder what alternative course the past might have taken if great ancient cultures had crossed paths. In fact, it is not widely known that some great civilisations of the past did come into contact, like in the case of China and ancient Greece, or more precisely, a Hellenised Kingdom called Dayum located in the easternmost part of the Hellenistic world, covering Bactria and Sogdiana in Central Asia from 250 to 125 BC. 
The Greeks of this region were discovered by China during the expedition of traveller Zhang Qian and had to fight against the Han dynasty during the War of the Heavenly horses between 104 and 101 BC. This war changed the fate of the region, and contributed to the creation of the Silk Road.
The war was fought between the Chinese Han dynasty and the Helelnised Kingdom of Dayuan initiated by the warlike Emperor Wu of Han as he coveted a breed of powerful horses called the “Heavenly Horses” in the region. After a 3-year period in which the Han armies suffered heavy losses, the war ended with the victory of the Chinese Empire resulting in the appointment of a new king in Dayum who pledged his alliance to Han. 
The Dayuan were the descendants of the Greek colonists that were settled by Alexander the Great in Ferghana in 329 BC 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. 
The land of Dayum had been ruled by Greeks generals and overlords for hundreds of years, after the death of Alexander the Great as part of the Seleucid Empire. While the region was eventually taken over by the indigenous Saka people who formed Dayuan, it remained a highly Hellenised country with soldiers of Greek ancestry. 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”.
video courtesy of YouTube channel Kings and Generals
