At the dawn of the last millennium, trading ships were sailing between India in the west and China in the east, across the Bay of Bengal and through the Straits of Malacca. Along the way, traders spread Indian culture – notably Hinduism and Buddhism, but also advances in the sciences and arts, the Sanskrit writing system and sophisticated models of statehood – across mainland Southeast Asia, as far east as the southern half of Vietnam, and down through the islands of Indonesia.