Writing system
Writing systems were preceded by proto-writing, systems of ideographic and/or early mnemonic symbols. The best known examples are:The invention of the first writing systems is roughly contemporary with the beginning of the Bronze Age in the late Neolithic of the late 4th millennium BC. The Sumerian archaic cuneiform script and the Egyptian hieroglyphs are generally considered the earliest writing systems, both emerging out of their ancestral proto-literate symbol systems from 3400 to 3200 BC with earliest coherent texts from about 2600 BC. It is generally agreed that Sumerian writing was an independent invention; however, it is debated whether Egyptian writing was developed completely independently of Sumerian, or was a case of cultural diffusion.
35th century BC
The 35th century BC in the Near East sees the gradual transition from the Chalcolithic to the Early Bronze Age. Proto-writing enters transitional stage, developing towards writing proper. Wheeled vehicles are now known beyond Mesopotamia, having spread north of the Caucasus and to Europe.Only approximate dating is usually possible for mid-4th millennium artifacts.See: List of sovereign states in the 35th century BC.