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.
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.