Esegels (aka Izgil (), Äsägel, Askel, Askil, Ishkil, pinyin Asijie, Sijie) were a, possibly,Turkic dynastic tribe that in the Middle Ages joined the Itil Bulgaria state and were assimilated to Bulgars; or was possibly a Bulgar tribe all along, as mentioned by Ibn Fadlan. Numerous records about Esegels in the sources in many languages, in connection with many historical subjects, and across the span of the Eurasian steppes left numerous variations of their name. M.Räsänen suggested Uralo-Altai etymology of this word: Es-kil, Es-gil "Old city", which may conflict with the older Chinese phonetization pinyin: Asijie.
Esegels were mentioned in the Chronography of Theophanes the Confessor (760-818): "the same month (July 563) ambassadors of Askil/Askel, the king of Hermihions (Greek Ερμηχιονιονων; Lat. Ermechionorum), a tribe living among barbarians near the ocean, came to Constantinople".
A Chinese annalistic account in 651 CE of the Western Turkic Khaganate Western Wing (on-shadapyt, Ch. Nushibi 弩失畢) division onto 5 tribes listed Esegels with a notation that the leader of first tribe Qiue-syjin "was most prosperous and strong, the number of his soldiers reached several tens of thousands". The leaders of the 5 tribes were listed as follows: