Khagan or Qaghan (Mongolian:; or Khagan; ) is a title of imperial rank in Turkic, Mongolic, and some other languages, equal to the status of emperor and someone who rules a khaganate (empire). The female equivalent is Khatun.
It may also be translated as "Khan of Khans", equivalent to King of Kings. In Bulgarian, the title became known as Khan, while in modern Turkic, the title became Khaan with the g sound becoming almost silent or non-existent; the ğ in modern Turkish Kağan is also silent. Since the division of the Mongol Empire, monarchs of the Yuan dynasty and the Northern Yuan held the title of Khagan. Kağan, Hakan and Kaan, Turkish equivalents of the title are common Turkish names in Turkey.
The common western rendering as Great Khan (or Grand Khan), notably in the case of the Mongol Empire, is a translation of Yekhe Khagan (Great Emperor or ).
Etymology
The term is of unknown origin and possibly a loanword from the Ruanruan language. Canadian sinologist Edwin G. Pulleyblank (1962) first suggested that a Xiongnu title, transcribed as (Old Chinese: *hʷaʔ-hʷaʰ) might have been the original behind Turkic qaɣan ~ xaɣan. According to Vovin (2007, 2010) the term comes from qaγan (meaning "emperor" or "supreme ruler") and was later borrowed and used in several languages, especially in Turkic and Mongolic.
Turkic and Mongolic (or Para-Mongolic) origin has been suggested by a number of scholars including Ramstedt, Shiratori, Pulleyblank, Sinor and Doerfer, and was reportedly first used by the Xianbei, as recorded in Book of Song. While Sinor believes qaγan or qapγan is an intensification of qan just as qap-qara is an intensification of qara "black", in Turkic (with the eventual loss of the p), Shiratori rejects a Turkic etymology, instead supporting a Mongolic origin for both qan and the female form qatun.
According to Vovin, the word *qa-qan "great-qan" (*qa- for "great" or "supreme") is of non-Altaic origin, but instead linked to Yeniseian *qεʔ ~ qaʔ "big, great". The origin of qan itself is harder according to Vovin. He says that the origin for the word qan is not found in any reconstructed proto-language and was used widely by Turkic, Mongolic, Chinese and Korean people with variations from kan, qan, han and hwan. A relation exists possibly to the Yeniseian words *qʌ:j or *χʌ:j meaning "ruler".
It may be impossible to prove the ultimate origin of the title, but Vovin says: "Thus, it seems to be quite likely that the ultimate source of both qaγan and qan can be traced back to Xiong-nu and Yeniseian".
Dybo (2007) suggests that the ultimate etymological root of Khagan comes from the Middle Iranian *hva-kama- ‘self-ruler, emperor’, following the view of Benveniste 1966. Savelyev and Jeong 2020 note that both the etymological root for Khagan and its female equivalent Khatun may be derived from Eastern Iranian languages, specifically from "Early Saka *hvatuñ, cf. the attested Soghdian words xwt'w ‘ruler’ (< *hva-tāvya-) and xwt'yn ‘wife of the ruler’ (< *hva-tāvyani)".
History
The title was first seen in a speech between 283 and 289, when the Xianbei chief Tuyuhun tried to escape from his younger stepbrother Murong Hui, and began his route from the Liaodong Peninsula to the areas of Ordos Desert. In the speech one of Murong's generals, Yinalou, addressed him as kehan (, later ); some sources suggests that Tuyuhun might also have used the title after settling at Qinghai Lake in the 3rd century.
The Rouran Khaganate (330–555) was the first people to use the titles Khagan and Khan for their emperors, replacing the Chanyu of the Xiongnu, whom Grousset and others assume to be Turkic. The Rourans were stated to be descendants of the Donghu people, who in turn are assumed to be proto-Mongols, Mongolic-speaking, or a "non-Altaic" group.
The Avar Khaganate (567–804), who may have included Rouran elements after the Göktürks crushed the Rouran ruling Mongolia, also used this title. The Avars invaded Europe, and for over a century ruled the Carpathian region. Westerners Latinized the title "Khagan" into "Gaganus" (in Historia Francorum), "Cagan" (in the Annales Fuldenses), or "Cacano" (in the Historia Langobardorum).