While clearing out my now-obsolete videotapes, I've been re-watching The 13th Warrior (1999): a nice film for those who like their mythology. Based on co-director Michael Crichton's book Eaters of the Dead, it's essentially a demythologized Beowulf with name changes: Beowulf is called Buliwyf, Hygelac called Hyglak, and the Grendel family transformed into the Wendol, a matriarchal cannibal tribe.
Both book and film introduce to the Beowulf story a narrator, Ahmad ibn Fadlan, an exiled Muslim who is conscripted by a group of Viking mercenaries as the required outsider, the "13th warrior", for their mission to defend a kingdom against mysterious attacks. The initial meeting draws on a real document, the Risala of Ibn Fadlan (see analysis at Viking Rus: studies on the presence of Scandinavians in Eastern Europe, Wladyslaw Duczko, Brill, 2004, ISBN 9004138749): an eyewitness account by an Arab chronicler who in 922 AD met Viking merchants - the Rus - active in the Volga region. Despite finding their lack of hygiene fairly repulsive, Ibn Fadlan evidently finds them an interesting people and doesn't demonise them in his account, even when witnessing a chief's funeral with human sacrifice.
The Viking Answer Lady's 13th Warrior Q&A has the text of the Risala and a historical/technical critique of the film. Yes, there are obvious anachronisms, but they don't detract from a very neat fantasy exploration of a classic story. It has a number of other good points, such as a positively-portrayed Muslim main character, and some clever set pieces, such as the telescoped language learning scene (1:40 here) where Ibn Fadlan is sitting with the Vikings on successive nights of their journey, and the dialogue he is hearing progressively morphs from Old Norse (represented in the film by, as far as I know, Norwegian) into English.