Sumerian. It is most convenient to describe the peoples of Mesopotamia and the surrounding regions ethnolinguistically, that is, in terms of the group affinities they assigned both to themselves and to each other and the languages they spoke. Throughout much of the third millennium B.C.E., the Sumerians formed the dominant group among the population of southern Mesopotamia. Whence they came and when they entered Mesopotamia are muchdebated questions to which there are at present no satisfactory answers. The language they spoke, Sumerian, is the oldest language for which there is evidence in the cuneiform writing system, which was developed in southern Mesopotamia toward the end of the fourth millennium B.C.E., not for the purpose of recording spoken language but rather for accounting and bookkeeping. The earliest texts are logographic, that is, each sign whether realistic or abstract in shape...