One of the earliest historical references to these mountains may be related to the Xiongnu word Qilian () - according to Tang commentator Yan Shigu, Qilian is the Xiongnu word for sky or heaven. Sima Qian in the Records of the Grand Historian mentioned Qilian in relation to the homeland of the Yuezhi and the term is believed to refer to the Tian Shan rather than the Qilian Mountains further east now known by this name. The Tannu-Ola mountains in Tuva has the same meaning in its name (heaven/celestial mountains or god/spirit mountains). The name in Chinese, Tian Shan, is most likely a direct translation of the traditional Kyrgyz name for the mountains, Teñir Too. The Tian Shan is sacred in Tengrism, and its second-highest peak is known as Khan Tengri which may be translated as Lord of the Spirits.