Elteber
Elteber ( or "(h)elitbär"; Chinese 頡利發 "xié-lì-fā" < EMCh: *"γεt-li-puat") was the client king of an autonomous but tributary tribe or polity in the hierarchy of the Turkic khaganates including Khazar Khaganate. In the case of the Khazar Khaganate, the rulers of such vassal peoples as the Volga Bulgars (only until 969, after that they were independent and created a powerful state), Burtas and North Caucasian Huns were titled elteber or some variant such as Ilutwer, Ilutver (North Caucasian Huns), Yiltawar or İltäbär (Volga Bulgaria) (until 969). An Elteber (Almış) is known to have met the  famous Muslim traveller Ibn Fadlan and requested assistance from the Abbasids of Baghdad. The earliest extant mention of the term is for a ruler of the North Caucasian Huns in the 680s, referred to in Christian sources from Caucasian Albania as "Alp Ilutuer". The title was also mentioned in "Letter to Kültegin" in 732. It was used by rulers of pre-Islamic Volga Bulgaria during the period of their vassalage to the Khazars. Rásonyi (1942:92), apud Golden (1980:149), glossed an "il teber" as "one who steps on the "il" at the head of conquered tribes"; with "il" descending from Proto -Turkic *"ēl" "realm" (Clauson, 1972:121; Sevortijan, 1974:339) whereas "täbär" from Turkic root *"täp-" "to kick with foot" (or *"tep-" / *"dēp-" "to stamp, tramp"). However, Erdal (2007:81-82) objects to Rásonyi's proposal: Erdal points out that "the Orkhon Turkic aorist of "täp-" would be "täpär"" and instead suggests a non-Turkic origin for the title. Róna-Tas (2016:72–73) proposes an Iranian etymology; he compares the Turkic title "(H)elteber" to Manichean Bactrian "l’dβr", Written Sogdian "δātβar", Sogdian "ryttpyr" / "dyttpyr" (*"litbir"), etc. from Middle Iranian *"lātbär" < Old Iranian *"dāta-bara" "who brings the law", ultimately from Proto-Indo-European roots *"dʰēH  to put, place" & "bʰer-" "to bring", respectively.