Kangar union was a Turkic state in the territory of the entire modern Kazakhstan without Zhetysu. The ethnic name Kangar is an early medieval name for the Kangly people, who are now part of the Kazakh, Uzbek, and Karakalpak nations. The capital of the Kangar union was located in the Ulytau mountains. The Pechenegs, three of whose tribes were known as Kangar (Greek: Καγγαρ), after being defeated by the Oghuzes, Karluks, and Kimek-Kypchaks, attacked the Bulgars and established the Pecheneg state in Eastern Europe (840–990 CE).
The Kengeres, mentioned in the Orkhon inscriptions, were possibly known in the Islamic world and in the west as Kangar, a collective name for three Pecheneg tribes (of eight). Byzantine emperor Constantine Porphyrogenitus stated that Kangar signified nobleness and bravery. Ukrainian historian Omeljan Pritsak suggested that Kangar originated from Tocharian A *kânk "stone" and Kengeres combined Kenger with the Iranian ethnonym As, supposedly from *ârs < *âvrs < *Aoruša (Greek: Αορσοι). However, Golden objected that *Aoruša would have yielded Ors/Urs and Pritsak's opinion on the Kengeres-Kangars' ethnonym and mixed Tocharian-Iranian origin remained "highly hypothetical". Other Orientalists, Marquart, Toltsov, Klyashtorny, attempted to connect the Kangar and Kengeres to the Qanglı, the eastern grouping of the Cuman-Kipchak confederation as well as the Indo-European Kangju in Chinese sources. Akhinžanov proposed that the Kipchaks simply assumed the name Qanglı (literally "wagon") after taking over the Kang region. András Róna-Tas (1996, 1999) proposes that the Pechenegs associated with their word kongor meaning "brown" (referring to their horses' coat color) with the ethnic name Kangar, which had been in existence in the Caucasus region as early as the 6th century CE before the Turkic peoples emerged; though he considers it a "case of an ethnic name established by means of a popular etymology". Nevertheless, all of these connections, if any, remain unclear.