Heinrich Graetz,
History of the Jews, Vol. 3 (of 6…
“ The Karaites gradually spread from Babylonia and Judæa to Egypt on the one side and to Syria on the other, and northwards as far as the Crimea. There were large Karaite communities in Alexandria and Cairo, and also in the Crimea, on the Bosporus (Kertch) , Sulchat and Kaffa (Theodosia) . The zeal of individuals contributed much to spread Karaism. By means of disputations, sermons, and letters, they endeavored to secure followers amongst the Rabbanites. Like every other essentially weak sect the Karaites relied upon propaganda, as though numbers could atone for lack of real strength. ”
