Khazars

There are two kinds of Khazars:

Harkavy was responsible for spreading the idea that the Gentile Taurian-Khazars are the same as the Jewish Carpathian Cozar People but there is no evidence that the Taurian-Khazars adopted Judaism rather than a religion referred to in Christian sources as the Heresy of Zembra the Khazar in the 860s. It is possible that Zembra followed the religion of the Taurian Godfearers. Before Harkavy there was Benjamin Aga who argued that his religion was descended from Taurian Khazars. But the only evidence of anything remotely Judaic from Taurian-Khazaria is an Arabic "Musa" coin which might rather indicate an heretical Islamic sect. Some have tried to argue that a six-flamed sun-disk symbol discovered resembles a Magen David.

In contrast, there is good evidence that the Kothrag who inhabited the Pannonian plains were converted to Judaism in the 700s and that the Haplogroup E-Y6940 genetic bottleneck ancestor of many Central European Jews was indeed one Romaniote Jew corresponding, therefore, to Yizhak Ha-Sangari who converted a good number of the Kothrags he found there in the 740s according to Jewish traditions. The area was called Kazarorszaga by the Hungarians. Kozar is the name of a town from 1335 near Carei in Satmar province while Cuzdrioara is latin for Kozar-var meaning Kozar-Fortress. There can be no doubt that the king of this fortress is the king referred to as Al-Kuzari. The Jews of Transylvania soon settled throughout the Polish Lithuanin commonwealth. After the partitions of Poland-Lithuania, many Jews found themselves in the Russian Empire so Harkavy and Firkovich were trying to project this story onto the Taurian Khazars to give themselves a sense of belonging in the Russian Empire. Benjamin Aga's research prove to be more plausible for the 18th Century Russian Imperial Authorities than Harkavy's later research which has only led to anti-Semitic conspiracy theories.

The Khazar Khagans were:

Ziebel c.628
Chouvertou(Chorpan Tarkhan)
Batbayan-Bezmer
Alp/Irbis
d. 715 Busir (Ibuzir Glavan) of Phanagoria
Parsbit/Prisbit & Tarmach
715-732 Bihar father of Empress Irene
Barjik son of Bihar

Then the the House of Aba 's Cozar People in Transylvania converted to become a new nation under their own line of Bulanid rulers based in Halych-Kiev completely independent from the non-Jewish Ashina Khazar Khagans of Turian-Khazaria. The known lineage of Bulanid Kohens of the Kabar people in Halych-Kiev is:

Sabriel c.740
Obadiah
Hezekiah
Manasseh I
Hanukkah,
(Khan-Tuvan a.k.a. Dyggvi seceded c.830)
the brother of Obadiah; next (814-?)
Isaac, his son; afterwards (?-835)
his son Zebulun
then his son Moses-Menasseh
then his son Nisi
then his son Aaron I
then his son Menahem
then his son Benjamin
then his son Aaron II
Joseph 950s-960s

Meanwhile Gentile Tarkhans continued to rule in Taurian-Khazaria under the Byzantines:

Hazer Tarkhan
Baghatur Ras Tarkhan
Zachariah 860 (Cherson) converted by St. Cyril & Methodius.
David 986-988 (Taman)
Georgius Tzul ?-1016 (Kerch)