Babylonia, an ancient country that occupied the area of southwestern Asia that is now Iraq. It was located in the fertile valley of the Tigris and Euphrates rivers in southern Mesopotamia. Two great empires developed there—the Old Babylonian in the 18th century B.C. and the Neo-Babylonian (or Chaldean) in the seventh century B.C.
Babylonia began as a small kingdom centered around the city of Babylon and eventually spread over southern Mesopotamia. At its greatest extent, Babylonian power stretched from the Persian Gulf north into Assyria and west to the Mediterranean Sea. where it extended from Syria south to Egypt. In later times, Babylonia was also called Chaldea—after the Chaldeans, a Semitic people from the desert of Arabia who had settled there about the 11th century B.C.