Smaller regional centers across the north, under Kushan control in the early centuries of the first millennium A.D., are brought together under the Gupta dynasty in the fourth century. Mahayana Buddhism flourish; the earliest paintings preserved in India (fifth-century cave paintings) depict the Buddha and scenes from his life. Buddhism spreads to Central Asia and China along international trade routes. The religion known as Hinduism assumes ritual and artistic form, and Hindu sculptures and temples proliferate. India trades with Rome and other cultures to the west, including Southeast Asia.