The al-Idrisi mountains are named for the late Islamic Golden Age geographer, Mohammed Al-Idrisi (1099-1165) who is most famous for the maps he created while a member of the court of the Christian & Norman King Roger II of Sicily. The map/book was a compilation of Islamic mariner and merchant reports, in Latin "Opus Geographicum" and "Tabula Rogeriana".
It detailed accurately the lands and seas from Europe to the East Indies and a Eurasia and N.Africa map was inscribed on a solid silver disc (2 meter diameter) as a presentation for King Roger. While the disc did not survive long, at least 10 copies of the manuscript have.
Thanks SES1066.