Beihaqi History, an authentic historical record from Qaznavi Dynasty

We would have forgotten useless kings of Qaznavi, if everyone other than Beihaqi had written the ugly history of the Qaznavis. The history of Iran would have lost in Qaznavi era like the time of many unknown local emperors and kings, if Beihaqi had not existed. I should say here that this is an astounding enigma that Qaznavis had renowned historians such as Bou Naser Moshkan and Abolfazl Beihaqi, and its also strange that Qaznavi Emirs highly re­spected these cultural figures.