Recorded history
More complete writing systems were preceded by proto-writing. Early examples are the Jiahu symbols (c. 6600 BCE), Vinča signs (c. 5300 BCE), early Indus script (c. 3500 BCE) and Nsibidi script (c. before 500 CE). There is disagreement concerning exactly when prehistory becomes history, and when proto-writing became "true writing" However, 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 BCE. 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 3400–3200 BCE with earliest coherent texts from about 2600 BCE.
Celts
The Proto-Celtic language is usually dated to the Late Bronze Age. The earliest records of a Celtic language are the Lepontic inscriptions of Cisalpine Gaul (Northern Italy), the oldest of which predate the La Tène period. Other early inscriptions, appearing from the early La Tène period in the area of Massilia, are in Gaulish, which was written in the Greek alphabet until the Roman conquest. Celtiberian inscriptions, using their own Iberian script, appear later, after about 200 BC. Evidence of Insular Celtic is available only from about 400 AD, in the form of Primitive Irish Ogham inscriptions.