Many of the Karaite manuscripts in this collection were acquired by Levinus Warner (1619–1665), whose library was purchased in 1669. Warner was an orientalist of German descent who for many years served as a representative of the Dutch government in Istanbul. He collected (and studied) a great number of oriental manuscripts in Hebrew, Arabic and other languages. Of particular interest were his contacts with the Karaite community of Istanbul, which for him, as a Protestant, had a specific fascination. Warner purchased a large number of manuscripts, including approximately thirty Karaite manuscripts. One of his acquisitions was a Karaitic compendium of no less than 23 texts (Or. 4779). Warner's personal notes in many of the Karaite manuscripts testify to Warner's special interest in Karaite Judaism.

Another source for this collection Karaitica was the library of Jehuda Gur b. Menachem (Or. 4752 and Or. 4779).

Karaite Judaism is a Jewish religious movement of a scripturalist and messianic nature, which emerged around the 9th century in the areas of Persia and Palestine. The Karaites reject allegorical and kabbalistic interpretations and those Talmudic rituals and rabbinic oral laws which are not founded in the Holy scriptures. The development of Karaism was characterised by various disputes on the literal interpretation of the Bible. Aaron ben Elijah of Nicomedia (1317-1369) wrote his code Etz Hayyim, which was recognised as authoritative. Later on it was Elijah Bashyazı and his pupil Caleb Afendopolo (1464-1525) who summarised the Karaite creed in ten articles. Among them the fifth says: "He sent us the Torah through Moses, which contains the perfect truth, which cannot be complemented or altered by any other (Oral) Law".