The Sumerians lived in Mesopotamia, in the lower valleys of R.Tigris and R.Euphrates in present day S. Iraq. Sumerian writing is generally considered to be the earliest writing system. It expanded outside Mesopotamia and was adapted by other peoples, becoming used in the area now known as the Middle East.
Development of Sumerian Cuneiform
Logographic form
Archaeologists believe that Sumerian writing arose out of pieces of clay that were used for purposes of record keeping. The Sumerians were a commercial people and logographic markings have been found on clay envelopes containing clay shapes e.g animal forms. It is thought that this was a form of book keeping. Sumerian logographic markings consisted of about 1200 different characters representing numerals, names and objects.
Cuneiform
Sumerian writing was a picture writing system that used symbols. When the Sumerians started using pointed instruments to make symbols, the shape of their writing changed. This type of writing was called cuneiform. Cuneiform was a word writing system because the forms represented whole words. Cuneiform therefore was not a language but a picture writing system that used symbols. These symbols came to be known and accepted even by ethnic groups that spoke different languages and dialects.
Development of the phonographic principle
Cuneiform expanded outside Mesopotamia and was adopted by the Akkadians,
the Babylonians and the Assyrians. Eventually, cuneiform became an almost universal form of written communication in the Middle East. Though the Sumerian writing remained largle logographic, the people who borrowed cuneiform adopted it into a partially syllabic form whereby a particular mark could represent a syllable or a whole word. Thus, they greatly expanded and developed the idea of sound-symbol correspondence in their adopted script. However, the Assyrian and Babylonian empires fell and cuneiform came to be used less and less as it could not compete with the alphabetic systems being developed by the Mediterranean peoples e.g. the Greeks.