The ED III (2600–2350 BC) saw an expansion in the use of writing and increasing social inequality. Larger political entities developed in Upper Mesopotamia and southwestern Iran. ED III is usually further subdivided into the ED IIIa (2600–2500/2450 BC) and ED IIIb (2500/2450–2350 BC). The Royal Cemetery at Ur and the archives of Fara and Abu Salabikh date back to ED IIIa. The ED IIIb is especially well known through the archives of Girsu (part of Lagash) in Iraq and Ebla in Syria.