Research in Syria has shown that developments there were quite different from those in the Diyala river valley region or southern Iraq, rendering the traditional Lower Mesopotamian chronology useless. During the 1990s and 2000s, attempts were made by various scholars to arrive at a local Upper Mesopotamian chronology, resulting in the Early Jezirah (EJ) 0–V chronology that encompasses everything from 3000 to 2000 BC. The use of the ED I–III chronology is now generally limited to Lower Mesopotamia, with the ED II sometimes being further restricted to the Diyala river valley region or discredited altogether.