This article traces the development of the Godin III ceramic tradition of central western Iran through an examination of regional distributions of painted pottery styles pertaining to six phases. The sequence, which spans the time period from about 2600-1400 B.C., is based on stratigraphic excavations at Godin Tepe. Changes in the painted style permit fine grained chronological distinctions at most sites in the mountains of central western Iran. Several cautionary notes concern problems of working with previously excavated materials and the problems of making the inferential leap from pots to people. Nonetheless, the distribution of chronologically distinct painted pottery styles is found to reflect a dynamic process of socio-political and economic integration of a mosaic of localized ethnic groups into a loose confederation by Godin III:2 times. Political and economic pressure from the Mesopotamian lowlands to the west may have contributed to this development. On the other hand, even when homogeneity of ceramic decorative style was at its height, there were regional differences which may reflect ethnic boundaries. At end of the sequence, the Godin III tradition fragments, possibly reflecting emergence of a simpler and more localized economy in which pastoralism is dominant.