What we know about the people of ancient Mesopotamia comes from excavations and the study of artifacts. This early “history” is divided into periods that chronologically order what we know. Before the invention of writing, distinct pottery styles, tools, and building techniques are used to subdivide the long “preliterate” era into time periods. Typically, these periods are named after the site where a distinctive style of pottery was first discovered. For example, the Ubaid period (6500–4000 BCE) is named after a distinctive style of pottery found at Ubaid. At Ur, pottery fragments of this style were found in the deepest levels of the excavation, indicating that Ur’s earliest occupation occurred during the Ubaid period.
Once writing began to record historical events, time periods began to be named after dominant political institutions. For example, the Early Dynastic period (2900–2250 BCE) is so called because we have written records (cylinder and stamp seals) that document the early royal dynasties of southern Mesopotamia. This period is subdivided into multiple sub-periods. At Ur, beneath the royal tombs, Woolley found 375 cuneiform tablets he dubbed “archaic text” and nearly 800 clay impressions of cylinder and stamp seals that date to the Early Dynastic I period (2900–2750 BCE).
During the Early Dynastic period at least two languages were used in southern Mesopotamia. Inscriptions written in both Sumerian (a language with no known descendants) and Akkadian (a Semitic language that developed into both Hebrew and Arabic) are found in Ur’s royal cemetery.