About 1185-1190 Moses Maimonides, rabbi, physician, and philosopher in Spain, Morocco and Egypt, wrote the Guide for the Perplexed, of which an early autograph draft is preserved in the Taylor-Schechter Cairo Genizah Collection at Cambridge University Library, gathered from the Genizah of the Ben Ezra Synagogue Old Cairo, along with several other autograph manuscripts and fragments by Maimonides. This document is Cairo Genizah T-S 10Ka4.1. A digital facsimile of the document is available from University of Cambridge Digital Library at this link.
Maimonides' Guide for the Perplexed, thought to have been completed by 1190,
"is the main source of the Rambam's philosophical views, as opposed to his opinions on Jewish law. Since many of the philosophical concepts, such as his view of theodicy and the relationship between philosophy and religion, are relevant beyond strictly Jewish theology, it has been the work most commonly associated with Maimonides in the non-Jewish world and it is known to have influenced several major non-Jewish philosophers. . . . Within Judaism, the Guide became widely popular and controversial, with many Jewish communities requesting copies of the manuscript."