毗伽可汗
The Turks were the first among the Central Asian peoples to develop a phonetic script. Stelae with texts written in the runic Orkhon script devoted to Tonyukuk, Bilge Khagan and Kul Tegin are found in the central regions of Mongolia. These texts telling about the wars which the militant Turks fought to defend their national freedom from alien enemies were first read by N. M. Yadrintsev and Wilhelm Tomson in the 1980s.