Cuneiform was a system of writing, dating from before 3000 BC until the early years AD. It used characters built up from wedge-shaped strokes (hence the term cuneiform, derived from the Latin word cuneus meaning a wedge), and most texts were written on clay tablets. The use of clay means that an enormous amount of material has survived, albeit in a fragmentary state, and we can now read letters, legal documents, omens, medical texts, and many other records written between two thousand and five thousand years ago. In its formative stage, with symbols scratched on clay tablets, rather than formed using the later wedge-shaped strokes, it is probably the earliest writing system in the world. An excellent introduction to cuneiform is given by C.B.F. Walker (Cuneiform, British Museum Press).

A cuneiform sign can stand for a whole word, or part of a word, or it can indicate that the following or preceding word is the name of a person, god, plant, fish, bird, etc. Many cuneiform signs can also take purely phonetic values. The earliest cuneiform tablets are lists, in which the signs are words (including numbers) or parts of words, and it is not obvious what language is being written. Grammatical elements, in the form of phonetic signs appear in about 2600 BC and it is then clear that the texts are in the Sumerian language. Later in about 2350 BC the Akkadian language was also written, and the script was adapted to write a variety of quite different languages: Elamite, Eblaite, Hurrian, Hittite, and a few others. The direction of writing was from left to right, except in some early texts where the signs are distributed in rectangular boxes, the boxes being read one after another in columns, from top to bottom, with the first column on the left.

The world’s first alphabet, for the Ugaritic language (spoken in Ugarit on the Syrian coast), used adaptations of cuneiform signs, and came into use between 1400 and 1300 BC.

For more on-line details about cuneiform see Wikipedia, and the Electronic Text Corpus in Oxford.