What is "tata-tonga"

Tata-tonga (, Mongolian script: , Tatatungүa) was a Yugur man involved in bringing and adapting the Old Uyghur alphabet to Mongolia in what is called the traditional Mongolian alphabet (Mongol bichig or hurdum bichig). He was captured by Genghis Khan in the 13th century and soon taught the Old Uyghur alphabet to members of the court and adapted it, to match Mongol Khalkha language, although Genghis (or Chingis) himself never learned it.

The Uyghur script was used in Mongolia until its independence to Qing dynasty China, at the beginning of the 20th century and few years before the Russia who introduced Cyrillic, takeover Mongolia. It is still used mainly in Inner-Mongolia. In current day Mongolia, mainly Cyrillic is used and sometime traditional Mongolian script. Today 6 millions Mongolians from China can still read the traditional script and only 3 million from Mongolia.

The Manchu alphabet was derived since the very end of the 16th century from this Mongolian script.