Southeast Asia was in the Indian sphere of cultural influence from 290 BCE to the 15th century CE, when Hindu-Buddhist influences were incorporated into local political systems. Kingdoms in the southeast coast of the Indian Subcontinent had established trade, cultural and political relations with Southeast Asian kingdoms in Burma, Thailand, Indonesia, Malay Peninsula, Philippines, Cambodia and Champa. This led to the Indianisation and Sanskritisation of Southeast Asia within the Indosphere, Southeast Asian polities were the Indianised Hindu-Buddhist Mandala (polities, city states and confederacies).