Various Mongolian writing systems have been devised for the Mongolian language over the centuries, and from a variety of scripts. The oldest and native script, called simply the Mongolian script, has been the predominant script during most of Mongolian history, and is still in active use today in the Inner Mongolia region of China and has de facto use in Mongolia. It has in turn spawned several alphabets, either as attempts to fix its perceived shortcomings, or to allow the notation of other languages, such as Chinese, Sanskrit and Tibetan. In the 20th century, Mongolia briefly switched to the Latin script, but then almost immediately replaced it with the Cyrillic script under the Mongolian People's Republic's for compatibility with the Soviet Union, as it was its satellite state. Nevertheless, Mongols living in Inner Mongolia as well as other parts of China, on the other hand, continued to use alphabets based on the traditional Mongolian script. In March 2020, the Government of Mongolia announced plans to use the traditional Mongolian script alongside the Cyrillic script in official documents (e.g. identity documents, academic certificates, birth certificates, marriage certificates, among others) as well as the State Great Khural by 2025, although the Cyrillic script could be used alone on an optional basis for less official writing. Precursors The Xianbei spoke a proto-Mongolic language and wrote down several pieces of literature in their language. They are believed to have used Chinese characters to phonetically represent Xianbei, like the Japanese system of Man'yōgana with Chinese, but all works written in Xianbei are now lost. In 2019, with the emergence of new evidence through the analysis of the Brāhmī Bugut and Khüis Tolgoi, Ruanruan language was deciphered, and Ruanruan was spelled in Brahmi script. The Khitan spoke another proto-Mongolic language and developed two scripts for writing it: Khitan large script and Khitan small script, logographic scripts derived from Chinese characters. Classic Mongolian script Traditional alphabet At the very beginning of the Mongol Empire, around 1204, Genghis Khan defeated the Naimans and captured a Uyghur scribe called Tata-tonga, who then adapted the Uyghur alphabet—a descendant of the Syriac alphabet, via Sogdian—to write Mongol. With only minor modifications, it is used in Inner Mongolia to this day. Its most salient feature is its vertical direction; it is the only vertical script still in use that is written from left to right. (All other vertical writing systems are written