The earliest scripts
Sumerians created cuneiform script over 5000 years ago. Pictograms representing actual things, were the basis for cuneiform writing.

Early pictograms resembled the objects they represented, but over time they began to look simpler. These marks eventually became wedge-shaped ('cuneiform'), and could convey abstract concepts.
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The cuneiform writing system

Alternative theory
Recently a discovery in southern Egypt challenges the theory that the first people to write were the Sumerians. The discovered hieroglyphics record linen and oil deliveries made over 5,000 years ago. The exact date of Sumerian writing remains in doubt but the new Egyptian discoveries have been confidently dated to between 3300 BC and 3200 BC using carbon isotopes.
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Where the Egyptions the first scribes?