The Kushan Empire and the Spread of Buddhism
The Kushans ruled the crossroads where India, Persia, China, and the Greek world met, and they taxed the Silk Road at its narrowest point. Their coins carry Greek letters, Persian and Hindu gods, and the earliest known image of the Buddha — a figure earlier Buddhists had refused to depict, and one whose face was carved in a Greek style left behind by Alexander's successors. Under Kushan protection, monks carried Buddhism north over the mountains toward China. A religion crossed a continent because an empire made the road safe and the tolls worth paying.
A belief system rises, spreads, institutionalizes, and then schisms — changing the rules people accept as legitimate.