During Tang China, the Silk Road's lingua franca in Central Asia was Sogdian, along which it amassed a rich vocabulary by loanwords such as tym 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, a region to the south of Sogdia, developed into 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, and Paul Pelliot, began investigating the Sogdian material that Pelliot had discovered. 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 the German Turfan expeditions. These expeditions were controlled by the Ethnological Museum of Berlin. These pieces consist almost entirely of religious works by Manichaean and Christian writers, including translations of the Bible. Most of the Sogdian religious works are from the 9th and 10th centuries. Dunhuang and Turfan were the two most plentiful sites of Manichean, Buddhist, and Christian Sogdian texts. Sogdiana itself actually contained a much smaller collection of texts. These texts were business related, belonging to a minor Sogdian king, Divashtich. These business texts dated back to the time of the Muslim conquest, about 700.
Writing system
Like all the writing systems employed for Middle Iranian languages, the Sogdian alphabet ultimately derives from the Aramaic alphabet. Like its close relatives, the Pahlavi scripts, written Sogdian contains many logograms or ideograms, which were Aramaic words written to represent native spoken ones. The Sogdian script is the direct ancestor of the Old Uyghur alphabet, itself the forerunner of the Traditional Mongolian alphabet. As in other writing systems descended from the Proto-Sinaitic script, there are no special signs for vowels. As in the parent Aramaic system, the consonantal signs ’ y w can be used as matres lectionis for the long vowels respectively. However, unlike it, these consonant signs would also sometimes serve to express the short vowels. To distinguish long vowels from short ones, an additional aleph could be written before the sign denoting the long vowel. The Sogdian language also used the Manichaean alphabet, which consisted of 29 letters. In transcribing Sogdian script into Roman letters, Aramaic ideograms are often noted by means of capitals.
