Although the Sumerian language is the oldest of the Near Eastern cuneiform languages , the ancient Persian language and the Akkadian language with the main dialects Babylonian and Assyrian were deciphered much earlier. Bilingual dictionaries from Nineveh were known early on , but their meaning was controversial for a long time. Jules Oppert was the first to recognize the independent language in 1869 and called it Sumerian . The existence of the language and thus of the Sumerian people - who did not call themselves "Sumerians" - was finally proven, but only 20 years later. Since 1877, Ernest de Sarzec and Léon Heuzey have unearthed various Sumerian language certificates in the capital of the Sumerian state of Lagaš , Girsu . In 1909, François Thureau-Dangin managed to decipher the Sumerian language and thus to establish Sumerology as a science.