Various, Encyclopaedia Britannica, 11th Edition…
“ It occurs in its present form for the first time in the account of the embassy sent in 569 by the East Roman emperor Justin II. to the Uighur Khan, Dugla-Ditubulu, where it is stated that this prince presented a slave of the Kirghiz tribe to Zemark, head of the mission. In the Chinese chronicles the word assumes the form Ki-li-ki-tz’, and the writers of the Yuan dynasty (1280-1367) place the territory of these people 10,000 li north-west of Pekin, about the headstreams of the Yenisei. ”
