Eaters Of The Dead

The novel is set in the 10th century. The Caliph of Baghdad Al-Muqtadir sends his ambassador, Ahmad ibn Fadlan, to the king of the Volga Bulgars. He never arrives but is instead conscripted by a group of Vikings to take part in a hero's quest to the north. Ahmad ibn Fadlan is taken along as the thirteenth member of their group to comply with a soothsayer's requirement for success. There they battle with the 'mist-monsters', or 'wendol', a tribe of vicious savages (possibly relict Neanderthals) who go to battle wearing bear skins.