At its height under King Kanishka, the Kushan Empire was one of the four great powers of the world, alongside Rome, Han China, and Parthia. Strategically located at the crossroads of the Silk Road, the Kushans grew wealthy by controlling and taxing the trade between East and West. They were a cosmopolitan empire that blended Greek, Persian, and Indian cultures. Kanishka is famous for convening the Fourth Buddhist Council and for his patronage of Mahayana Buddhism, which he helped spread to China via the Silk Road. Kushan coins are a fascinating historical record, featuring a mix of deities including the Buddha, Greek gods like Helios, and Persian spirits. Their empire was a vital 'cultural bridge,' facilitating the exchange of art, religion, and philosophy that would shape the future of Asia. Their decline in the 3rd century CE paved the way for the rise of the Sassanids and the Guptas.