The history of Indonesia has been shaped by its geographic position, natural resources, a series of human migrations and contacts, wars and conquests, as well as by trade, economics and politics. Indonesia is an archipelagic country of 17,000 to 18,000 islands stretching along the equator in Southeast Asia and Oceania. The country's strategic sea-lane position fostered inter-island and international trade; trade has since fundamentally shaped Indonesian history. The area of Indonesia is populated by peoples of various migrations, creating a diversity of cultures, ethnicities, and languages. The archipelago's landforms and climate significantly influenced agriculture and trade, and the formation of states. The boundaries of the state of Indonesia match the 20th-century borders of the Dutch East Indies.