Horses

node

The commodity that moved east, and the reason the Han state opened the western routes at all. Zhang Qian's reports described the tall horses of Ferghana, called tianma or heavenly horses in Chinese sources and known as blood-sweating horses, a description now generally attributed to a parasitic infection. Chinese cavalry needed mounts that steppe and Central Asian breeders could supply and Chinese pasture could not, and Emperor Wu fought a war against Dayuan in Ferghana from 104 to 101 BCE to secure them. Later dynasties institutionalised the exchange, trading silk to the Uyghurs and tea to Tibet for horses. A traded commodity, not a place.

A node is not a place. Drawing it on a map would assert something about the world that no stored fact supports.