The Middle East is a geographical region of Western Asia located between the Indian Subcontinent to the east, Central Asia to the northeast Africa to the southwest, the Caucasus to the north, and the Balkans to the northwest. The region has been a major part of history since the start of civilization, with early civilizations such as Sumer, Babylon, Ur, Uruk, and Assyria flourishing then; in recent years, it has been an important source of oil as well as a battleground for primarily-Sunni Salafist insurgents. Almost all of the countries in the Middle East have a Muslim majority, with most of those countries specifically having a Sunni Muslim majority; Israel is mostly Jewish and Lebanon has a 45% Christian minority. Great cities such as Jerusalem, Istanbul, Tehran, Mecca, Medina, Baghdad, and Cairo are located in the Middle East.