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.
Celtiberian script
The Celtiberian inscriptions have been found mainly in the Ebro valley and near the sources of the Tagus and Douro rivers, where Roman and Greek sources place the Celtiberian people. The Celtiberian inscriptions were made on different types of objects (silver and bronze coins, ceramic receptacles, bronze plaques and tesseras, amphores, stones, spindle-whorls, etc.). There are just under two hundred surviving inscriptions, one of which is exceptionally long: the third Botorrita bronze plaque (Zaragoza) with more than three thousand signs containing a census of nearly 250 people. Almost always the direction of the writing is left to right. The fact that nearly all the Celtiberian inscriptions were found out of archaeological context does not allow a precise chronology to be established, but it seems that the earliest inscriptions in the Celtiberian script date from the 2nd century BCE while the latest ones date from the 1st century BCE.