the Protoliterate period (ca. 3400–2900).7 The earliest written tablets come from the sites of ancient Uruk and Jemdet Nasr (with a scattering from other places, especially in the Diyala region) and date from as early as 3100. The language of these texts appears to be Sumerian, suggesting that the Sumerians invented writing. Some scholars argue for a non-Sumerian substratum in the Sumerian language, which would point to another and possibly an earlier ethnic group that was incorporated into the Sumerian