This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Ask which language humanity wrote down first and the answer, so far as the archaeological record shows, is Sumerian. In the city of Uruk in southern Mesopotamia, scribes began pressing marks into wet clay tablets around 3400 to 3200 BCE, at first simple pictographs and tallies used to track grain, livestock and labor for temple households. Within a few centuries those pictographs had been abstracted into the wedge shaped strokes of cuneiform, pressed with a cut reed stylus rather than drawn, and the script had grown flexible enough to record not just numbers but Sumerian's own spoken grammar, its verbs, pronouns and particles. This makes Sumerian the language behind the earliest known writing system, predating Egyptian hieroglyphs and the Indus script by a matter of centuries by most reckonings. Sumerian itself is a language isolate, unrelated to any other known language living or dead, which means cuneiform was invented to write a tongue with no linguistic relatives to compare it against. The scribal schools that grew up around this new technology, called edubba, houses of tablets, trained generations of administrators, and their students copied out not only accounts but hymns, proverbs and the world's oldest recorded works of literature, centuries before Sumerian ceased to be anyone's native spoken language and lived on as the learned, liturgical tongue of Mesopotamian scholarship.