Southeast Asia is a collective name for the lands lying to the east of the Indian subcontinent and to the south of China. Its regional unity derives in the main from its transitional character between the two great demographic and cultural foci of India and China. It consists of the Asian mainland and fringing islands, with a population of nearly 552 million. Southeast Asia has great diversity in its population, resources, and political and economic patterns. Perhaps no area in the world has been swept by so many tides of military, mercantile, and cultural influence as Southeast Asia, and few areas preserve the relics of those influences in such astonishing and appealing variety.