Yuezhi nomads built an empire from Bactria to the Ganges
The Kushan Empire (about 30–375 CE) began when Yuezhi migrants settled Bactria and expanded across Afghanistan, northern India, Pakistan and Central Asia. Chinese sources list them as one of five Yuezhi aristocratic tribes; their coins and roads knitted Greek, Iranian and Indian worlds.
The story starts on the grasslands of eastern Xinjiang and Gansu. Chinese histories say the Yuezhi lived there until the Xiongnu beheaded their king, driving them west between 176 and 160 BC. They reached Greco-Bactria, in today's northern Afghanistan and Uzbekistan, around 135 BC, pushing Greek dynasties south toward the Hindu Kush and the Indus. Scholars still debate their roots, variously proposing Indo-European, Tocharian or Saka origins; a 2013 genetic study of burials argued the Yuezhi and Tocharians were distinct peoples.
In the 1st century BC the Guishuang branch rose over the others and, under its commander Kujula Kadphises, forged them into a tight confederation. The West turned the name into Kushan, while China kept calling them the Yuezhi. Kujula borrowed Greek and Iranian imagery for his many coins and was a Shaivite. His son Vima Takto pushed into northwestern India; his grandson Vima Kadphises, ruling about 95 to 127, added more of Bactria.
The fourth king, Kanishka the Great, reigned about 23 years from roughly 127. The Rabatak inscription lists cities under his sway reaching to Ujjain and beyond Pataliputra, and he governed from Purushapura, modern Peshawar, and Mathura, with a summer seat at Kapisa near Bagram. There, excavators found the Treasure of Begram, artworks gathered from Greece to China. His armies crossed north of the Karakoram, and a road from Gandhara to China stayed in Kushan hands for over a century, helping carry Mahayana Buddhism into China. Kushan courts also traded envoys with Rome.
Official business moved from Greek to the Bactrian language, and provinces were run by satraps. By the 3rd century the realm had split into semi-independent kingdoms; Sasanians took the west, the Guptas pressed from the east, and Kidarite invaders finished the last Kushan states.
Source: Kushan Empire
