The Chaldeans were people who lived in southern Babylonia which would be the southern part of Iraq today. Sometimes the term Chaldeans is used to refer to Babylonians in general, but normally it refers to a specific semi-nomadic tribe that lived in the southern part of Babylon. The land of the Chaldeans was the southern portion of Babylon or Mesopotamia. It was generally thought to be an area about 400 miles long and 100 miles wide alongside the Tigris and Euphrates Rivers.