Yitzhak ha-Sangari [SEP] occupation
Yitzhak ha-Sangari
Yitzhak ha-Sangari is the name of the rabbi who converted the Khazar royalty to Judaism according to medieval Jewish sources. According to D. M. Dunlop, "the name Isaac Sangari is perhaps not attested before the 13th century, when he is mentioned by Nahmanides."
In "Sefer ha-Emunot" ("Book of Beliefs"; early 15th century), Rabbi Shem Tov ibn Shem Tov wrote: 
I have been preceded by Rabbi Yitzhak ha-Sangeri, companion [haver]
, with the permission of the Assyrian king into the Crimean peninsula. He also claimed to have found the tombstone of Yitzhak ha-Sangari and his wife who he claimed were Karaims. Whether Firkovich forged some of the tombstone inscriptions and manuscripts is controversial.
Regarding the origin of the Karaims in Lithuania also there is no complete consensus yet between the scholars. According to Lithuanian Karaim tradition they came from Crimea in 1392 when the Grand Duke Vytautas of Lithuania allied with Tokhtamysh against the White Horde Tatars and relocated 330 Karait families to