Sumerian literature
Sumerian literature constitutes the earliest known corpus of recorded literature, including the religious writings and other traditional stories maintained by the Sumerian civilization and largely preserved by the later Akkadian and Babylonian empires. These records were written in the Sumerian language in the 18th and 17th Centuries BC during the Middle Bronze Age. The Sumerians invented one of the first writing systems, developing Sumerian cuneiform writing out of earlier proto-writing systems by about the 30th century BC. The Sumerian language remained in official and literary use in the Akkadian and Babylonian empires, even after the spoken language  disappeared from the population; literacy was widespread, and the Sumerian texts that students copied heavily influenced later Babylonian literature. Poetry. Most Sumerian literature is written in left-justified lines, and could contain line-based organization such as the couplet or the stanza, but the Sumerian definition of poetry is unknown. It is not rhymed, although “comparable effects were sometimes exploited.” It did not use syllabo-tonic versification, and the writing system precludes detection of rhythm, metre, rhyme, or alliteration. Quantitative analysis of other possible poetic features seems to be lacking, or has been intentionally hidden by the scribes who recorded  the writing. Literary genres and topics. Based on the categorization work of Miguel Civil, Modern assyriologists have divided the extant corpus of sumerian literature into broad categories including "Literary Catalogs", "Narratives and Mythological Compositions", "Historical Compositions and Praise Poetry", "Letters, Letter Prayers and Laws", "Hymns and Songs", "Heterogenous Compositions" (including Wisdom literature), and "Proverbs".