The Karimi (Crimeans) were once famous as merchants who controlled the trade routes through (Persian: Karima).
Jewish communities existed in many of the Greek colonies in the region during the late classic period. Recently excavated inscriptions in Crimea have revealed a Jewish presence at least as early as the 1st century BCE. In some Crimean towns, monotheistic pagan cults called Hypsistarians or sebomenoi theon hypsiston ("Worshippers of the All-Highest God," or "God-Fearers") existed. These quasi-proselytes kept the Jewish commandments but remained uncircumcised and retained certain pagan customs. This became the basis of the Crimean religion of the Karimi which was adopted by Khazars.
The 40 families of Karaite-Turks settled in Bakhchisarai crrtainly adopted this religion when they arrived and mixed with the Ghisolfi family.
In the 15th century their religion was already widespread in Novgorod and wad represented in Moscow by Elena of Moldavia and her son the Crown Prince Dimitry. However, Sofia Palaiologina started to bring the Russian church into alignment with Greece instead and cracked down on the Karimi who had to seek refuge with the Ghisolfis in the Crimean Khanate.
In 1795 the Crimean Karaites petitioned Count Zubiv pretending to be Karimi instead of Jews in order to escape a double taxation law which applied to Jews initiating a relationship between the Karimi and the Karaites which culminated in Seraya Shapshal promoting a short lived union between the two in 1919. However, the Ukrainian Karaites expelled Shapshal and united with the Nazis in WW2 to exterminate the Karimi Karaitizers.