Writing
The invention of the first writing systems is roughly contemporary with the beginning of the Bronze Age 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.
Proto-writing
However, there are number of interpretations regarding symbols found on artefacts of the European Bronze Age which amount to interpreting them as an indigenous tradition of proto-writing. Of special interest in this context are the Central European Bronze Ages cultures derived from the Beaker culture in the second half of the 2nd millennium BCE. Interpretations of the markings of the bronze sickles associated with the Urnfield culture, especially the large number of so-called "knob-sickles" discovered in the Frankleben hoard, are discussed by Sommerfeld (1994).