The Sumerians of southern Mesopotamia invented writing, the city, the administrative bureaucracy, and the concept of codified law — a cluster of innovations so fundamental that understanding how they emerged in one place over one relatively short period has been a central puzzle of ancient history.

Writing emerged around 3200 BC in the Sumerian city of Uruk, initially as an accounting system. The first written documents are not literature or history but records of goods received and disbursed — the administrative needs of a complex redistributive economy generated the first writing system. The move from token-based accounting (clay tokens of different shapes representing different goods) to the two-dimensional representation of those tokens on clay tablets is the origin of writing.

The earliest cities — Uruk, Eridu, Nippur, Ur — grew to populations of tens of thousands in the 4th millennium BC, requiring entirely new forms of social organization. The Sumerian city was organized around the temple complex, which was simultaneously a religious center, storage facility, workshop, and administrative unit. The temple managed the redistribution of agricultural surplus, organized craft production, maintained the irrigation system, and performed the religious rituals that maintained cosmic order.

Sumerian literature, recovered from clay tablets across sites in Iraq over the past 150 years, is both older and larger than many appreciate. The Hymn to Inanna, the Descent of Inanna to the Underworld, the Debate between Winter and Summer, the Dialogue of a Man with his God (sometimes called the Sumerian Job) — these texts from the 3rd millennium BC address themes of love, death, suffering, and divine justice that reappear in the Hebrew Bible and in subsequent Western literature.