Yusuf Balasaghuni, Yusuf "Khass Khajib" Balasaghuni was an 11th century Uyghur scribe from the city of Balasaghun, the capital of the Karakhanid Empire. He wrote the Kutadgu Bilig and most of what is known about him comes from his own writings in this work.
Balasagun was located near present-day Tokmok in Kyrgyzstan. Yusuf Has Hajib was about 50 years old when he completed the Kutadgu Bilig. After presenting the completed work to the prince of Kashgar he was awarded the title Kha?? ?ajib, an honorific similar to "Privy Chamberlain" or "Chancellor".
He is often referred to as either Yusuf Balasaguni or Yusuf Khass Hajib.
Some scholars suspect that the prologue to the Kutadgu Bilig, which is much more overtly Islamic than the rest of the text, was not written by Yusuf, particularly the first prologue, which is in prose, unlike the rest of the text.
He is entombed in his mausoleum in Kashgar.