Cuneiform was the system of writing used most extensively in the ancient Middle East. Cuneiform was employed for writing a number of languages from about the end of the 4th millennium BC until about the 1st century BC.
The earliest attested documents in cuneiform were written in Sumerian, the language of the inhabitants of southern Mesopotamia and Chaldea from the 4th until the 2nd millennium BC. Discovered at the site of the ancient city of Uruk (biblical Erech), they were in a pictographic type of cuneiform in which objects were represented by pictures, numbers were represented by the repetitional use of strokes or circles, and proper names were indicated by combinations of pictures used according to the rebus principle; i.e., the pictures were to be interpreted according to their usual pronunciations rather than according to the objects they depicted.
About the 3rd millennium BCE, the pictographs gradually began to change to conventionalized linear drawings and because they were pressed into soft clay tablets with the slanted edge of a stylus, came to have a wedge-shaped appearance. Earlier cuneiform was written in columns from top to bottom but during the 3rd millennium came to be written from left to right with the cuneiform signs turned on their sides. At about the same time these changes in the cuneiform writing system were occurring, it was adopted by the Akkadians, Semitic invaders of Mesopotamia, for writing their language. The earliest Akkadian cuneiform inscriptions date from the Old Akkadian or Early Akkadian period (c. 2450 to c. 1850 BC), during which the inscriptions of Sargon, the great ruler of Akkad, were written. Cuneiform continued to be used for writing the Assyrian and Babylonian dialects descended from Akkadian.
Cuneiform was borrowed by the Elamites, the Kassites, the Persians, the Mitanni, and the Hurrians. The Hurrians passed the cuneiform writing system on to the Hittites, who spoke an Indo-European language; cuneiform was also used for the languages (e.g., Luwian, Hattian) spoken in areas under Hittite control.
With the spread of Aramaic as the lingua franca of the Near East in the 7th and 6th centuries BC, the increasing use of the Phoenician script, and the loss of political independence in Mesopotamia with the growth of the Persian Empire, cuneiform came to be used less and less, although it continued to be written by many conservative priests and scholars for several more centuries. The latest known tablet in cuneiform dates from c. AD 75.The Old Persian part of the trilingual royal inscriptions of the Achaemenid kings of Persia were the first cuneiform documents to be deciphered. The inscriptions were also written in Elamite, which still has not been completely deciphered and investigated, and Akkadian, which was deciphered as soon as scholars recognized it to be a Semitic language. Once Akkadian had been deciphered, the complete cuneiform system became intelligible and the other languages written in cuneiform could be read. Sumerian, at first believed to be a special way of writing Akkadian rather than a separate language, was among the last of the languages written in cuneiform to be deciphered.