His personal name recorded in Chinese sources was
Ashina Kolo () which is reconstructible in
Middle Chinese as *
kʰuâ-lâ according to
Peter Golden. According to him, this was a transliteration of the . His regnal name Yixiji was reconstructed by Ahmet Taşağıl as
Ilji. He is also referred to as
Ayi Qaghan () in
Cefu Yuangui. Zhu Zhenghong, who analyzed his great-grandson Shi Shanying's epitaph, argued that in Turkic cosmology, colors correspond to cardinal directions, with "black" representing north. He proposed that "Kolo" was not his personal name, but a political title he held before becoming qaghan. As
Bumin's eldest son, he was stationed in the north to govern the
Tiele tribes, hence the title "Black" (
Qara). Epitaph referred to Issik as
Xiejiesuona Qaghan (). Zhenghong believes this was a regnal title that could be reconstructed as . Moreover, according to Zhu Zhenghong, Issik Qaghan's personal name was
Dayuan (), based on his analysis of
Ashina Zhong's tomb. == Rule ==