The Sogdian language was an Eastern Iranian language spoken mainly in the Central Asian region of Sogdia (capital: Samarkand; other chief cities: Panjakent, Fergana, Khujand, and Bukhara), located in modern-day Uzbekistan, Tajikistan, Kazakhstan and Kyrgyzstan; it was also spoken by some Sogdian immigrant communities in ancient China. Sogdian is one of the most important Middle Iranian languages, along with Bactrian, Khotanese Saka, Middle Persian, and Parthian. It possesses a large literary corpus. The Sogdian language is usually assigned to a Northeastern group of the Iranian languages. No direct evidence of an earlier version of the language ("Old Sogdian") has been found, although mention of the area in the Old Persian inscriptions means that a separate and recognisable Sogdia existed at least since the Achaemenid Empire (559–323 BCE). Like Khotanese, Sogdian may have possessed a more conservative grammar and morphology than Middle Persian. The modern Eastern Iranian language Yaghnobi is the descendant of a dialect of Sogdian spoken around the 8th century in Osrushana, a region to the south of Sogdia. History During the period of the Chinese Tang dynasty (ca. 7th century CE), Sogdian was the lingua franca in Central Asia of the Silk Road, along which it amassed a rich vocabulary of loanwords such as tym ("hotel") from the Middle Chinese /tem/ (). The economic and political importance of Sogdian guaranteed its survival in the first few centuries after the Muslim conquest of Sogdia in the early eighth century. A dialect of Sogdian spoken around the 8th century in Osrushana (capital: Bunjikat, near present-day Istaravshan, Tajikistan), a region to the south of Sogdia, developed into the Yaghnobi language and has survived into the 21st century. It is spoken by the Yaghnobi people. Discovery of Sogdian texts The finding of manuscript fragments of the Sogdian language in China's Xinjiang region sparked the study of the Sogdian language. Robert Gauthiot, (the first Buddhist Sogdian scholar) and Paul Pelliot, (who while exploring in Dunhuang, retrieved Sogdian material) began investigating the Sogdian material that Pelliot had discovered in 1908. Gauthiot published many articles based on his work with Pelliot's material, but died during the First World War. One of Gauthiot's most impressive articles was a glossary to the Sogdian text, which he was in the process of completing when he died. This work was continued by Émile Benveniste after Gauthiot's death. Various Sogdian pieces have been found in the Turfan text corpus by