The Michael Crighton book, “Eaters of the Dead” (movie 13th Warrior) is loosely based on 7 translation of the Arab Ibn Fadan who came from what is now Baghdad.
The book is semi-fiction but based on the translations of an ancient diary of Ibn Fadn.
Theory goes that that the enemies that were harassing the Vikings were actually the last remnants of Neanderthals.
Love that lost Neanderthal lore. You know, Friedrich von Junzt, who wrote the Unaussprechlichen Kulten, claimed Neanderthals lived on, at least through the 16th century in a vast cave system under the Spanish Pyrenees, and were worshipped by various proto-Dionysian mystery cults, as well as later pagan state religions throughout Europe. Some even whisper today of Vatican couriers disappearing for months at a time into the Basque backcountry. At risk of being accused of cheezy viral publicity mongering, I will say that a friend in the movie business told me M. Knight Shamilan is working on something along these lines and is planning to play Pope of the Neanderthals himself.