Ancient Iraq was the home of a major urban civilization which developed during the fourth millennium BCE. Writing was an essential element of this culture, which spread throughout the ancient Middle East, especially up the riverine corridor along the Euphrates and into ancient Turkey. The term 'Mesopotamia' is often used not just strictly to refer to the area between the Tigris and the Euphrates, but by extension to refer to the cultural/geographical zone including Iraq, eastern Syria and parts of Turkey.
Sumerian was used throughout ancient Mesopotamia, especially in the area that now corresponds to southern Iraq. The earliest written texts in the world date to about 3200 BCE, and are probably written in Sumerian. Because Mesopotamian scribal culture was bilingual from the early third millennium BCE to the end of the first millennium BCE, Sumerian was used intermittently throughout the ancient Near East. Texts entirely or partly in Sumerian have been found in modern Turkey, Egypt, Syria, Iraq and Iran.
Sumerian is a language isolate, meaning that it has no relatives living or dead (though there have been unsuccessful attempts to connect Sumerian to a number of languages).
Sumerian is agglutinative; word roots have grammatical elements glued on before or after them to build up complex grammatical forms.
Writing in Mesopotamia begins its life as a pictographic and ideographic system. In other words, the earliest signs were pictures which represented ideas. The sign for 'mouth' could mean 'mouth', 'word', 'speak' and so on. The early system of drawing outlines of signs in clay with a pointed stylus rapidly gave way to a signs rendered with the squared edge of a reed stylus which have a characteristic triangular head and a pointed tail. This triangular shape is the basis for the name of this writing: cuneiform.
Sumerian writing always remained ideographic at heart, but the ideograms were soon supplemented by signs representing combinations of sounds, called 'syllabograms'. Many of these were derived by the 'rebus' principle; the sign for mouth was used to write the sound /ka/ because the word for mouth in Sumerian was 'ka'. This enabled the writing system to express both non-Sumerian personal names as well as grammatical markers.
The Sumerian text corpus is huge in ancient terms; at least 100,000 documents have been excavated over the last century or so and are now in museums throughout the world. Because clay is a durable medium for written records, it is certain that hundreds of thousands of texts still await discovery in the ancient ruin-mounds, particularly in Iraq and Syria.
Texts in Sumerian cover all genres. The most important corpus is that of the administrative texts from the Ur III period which is the primary concern of the CDLI project. Sumerian administrative texts hold huge promise for sophisticated research into the socio-political realities of governments and people in ancient times.
Sumerian literature also makes a significant contribution to our knowledge of early mythology, heroic narrative and political and religious ideology. The ETCSL project is preparing a web-based corpus of Sumerian literature.
Mesopotamian scribes have also left us thousands of tablets from their training in the form of wordlists, grammatical texts and exercise tablets. These are an invaluable resource for understanding Sumerian; the lexical corpus is being digitized by the DCCLT project.
Other text corpora include hundreds of monumental inscriptions commissioned by Mesopotamian kings, magical incantations and religious worship texts as well as inscriptions from cylinder seals.