The film was a financial failure. Production and marketing costs reputedly reached $160 million, but it grossed $61 million at the box office worldwide, making it one of the biggest box office bombs in history (23rd adjusted for inflation).
Ahmad ibn Fadlan is a court poet to the Caliph of Baghdad, until his amorous encounter with the wife of an influential noble gets him exiled as an "ambassador" to the Northern Barbarians. Traveling with Melchisidek, his caravan is saved from Turkic raiders by the appearance of Norsemen (presumably Varangian). Taking refuge at their settlement on the Volga river, communications are established through Melchisidek and Herger, a Norseman who speaks Latin. Ahmad and Melchisidek are in time to witness a fight, which establishes Buliwyf as heir apparent, followed by the Viking funeral of their dead king, cremated together with a young woman who agreed to accompany him to Valhalla.
A youth enters the camp requesting Buliwyf's aid: his father's kingdom in the far north is under attack from an ancient evil so frightening that even the bravest warriors dare not name it. The "angel of death", a völva (wisewoman), determines the mission will be successful if thirteen warriors go to face this danger—but the thirteenth must not be a Norseman. Ahmad is recruited against his will.
Ahmad learns Norse during their journey by listening intently to his companions' conversations. He is looked down upon by the huge Norsemen, who mock his physical weakness and his small Arabian horse, but he earns a measure of respect by his fast learning of their language, his horsemanship, ingenuity, and ability to write.
Reaching King Hrothgar's kingdom, they confirm that their foe is indeed the ancient "Wendol", fiends who come with the mist to kill and eat human flesh. While the group searches through a raided cabin they find a venus figurine. On their first night three of their number - Hyglak, Ragnar and Haltaf are killed. In a string of clashes, Buliwyf's band establishes that the Wendol are humanoid cannibals who appear as, live like, and identify with bears.
Their numbers dwindling and their position all but indefensible, an ancient völva of the village tells them to track the Wendol to their lair and destroy their leaders, the "Mother of the Wendol" and their Warlord who wears "the horns of power". Buliwyf and the remaining warriors infiltrate the Wendol cave-complex and kill the Mother, but not before Buliwyf is scratched deeply across the shoulder by her poisoned "fingernail claw".
The remaining warriors return to the village and prepare for a final battle they do not expect to survive. Buliwyf staggers outside before the fight and inspires the warriors with a Viking prayer for the honored dead who will enter Valhalla. Buliwyf succeeds in killing the Wendol Warlord, causing their defeat, before succumbing to the poison. Ahmad ibn Fadlan witnesses Buliwyf's royal funeral before returning to his homeland, grateful to the Norsemen for helping him to "become a man, and a useful servant of God". He is shown at the movie's end writing down the tale of his time with them.Antonio Banderas as Ahmed ibn Fadlan (13th Warrior)
Diane Venora as Queen Weilew
Vladimir Kulich as Buliwyf (1st Warrior)
Dennis Storhøi as Herger (Joyous) (11th Warrior)
Omar Sharif as Melchisidek
Clive Russell as Helfdane (Fat) (2nd Warrior)
Richard Bremmer as Skeld (Superstitious) (12th Warrior)
Tony Curran as Weath (Musician) (8th Warrior)
Eric Avari as Caravan leader
Sven Wollter as King Hrothgar
Asbjorn Riis as Halga (Wise) (10th Warrior)
Maria Bonnevie as Olga
Daniel Southern as Edgtho (Silent) (4th Warrior)
And also:Mischa Hausserman as Rethel (Archer)(5th Warrior)
Neil Maffin as Roneth (Rider)(6th Warrior)
John DeSantis as Ragnar (Dour)(9th Warrior)
Oliver Sveinall as Haltaf (Boy) (7th Warrior)
Albie Woodington as Hyglak (Quarrelsome) (3rd Warrior)
Susan Willis as Wendol Mother
Yolande Bavan as Wendol Mother Companion
Originally titled Eaters of the Dead, production began in the summer of 1997, but the film went through several re-edits after test audiences did not react well to the initial cut. Crichton took over as director himself due to the poor test audience reception, causing the release date to be pushed back over a year. The film was re-cut, a new ending added, along with a new score. Graeme Revell was replaced by Jerry Goldsmith as composer. The title was changed to The 13th Warrior.
The budget, which was originally around $85 million, reportedly soared to $100 million before principal photography wrapped. With all of the re-shoots and promotional expenses, the total cost of the film was rumored to be as high as $160 million, which given its lackluster box office take (earning US $61.7 million worldwide), made for a loss of $70–130 million.
The film debuted at No. 2 on its opening weekend behind The Sixth Sense.
The 13th Warrior holds a 33% approval rating on Rotten Tomatoes based on 87 reviews. The consensus is: "Atmospheric, great sets and costumes, but thin plot."
Roger Ebert gave the film one and a half stars out of four, remarking that it "lumber[s] from one expensive set-piece to the next without taking the time to tell a story that might make us care." Conversely, James Berardinelli gave The 13th Warrior three stars out of four, calling it "a solid offering" that "delivers an exhilarating 100 minutes". Lisa Schwarzbaum of Entertainment Weekly rated it A− and called it "the most unexpectedly audacious, exhilarating, and wildly creative adventure thriller I have seen in ages".
The outcome of the film's production disappointed Omar Sharif so much that he temporarily retired from film acting, not taking a role in another major film until 2003's Monsieur Ibrahim:
"After my small role in The 13th Warrior
, I said to myself, 'Let us stop this nonsense, these meal tickets that we do because it pays well.' I thought, 'Unless I find a stupendous film that I love and that makes me want to leave home to do, I will stop.' Bad pictures are very humiliating, I was really sick. It is terrifying to have to do the dialogue from bad scripts, to face a director who does not know what he is doing, in a film so bad that it is not even worth exploring."
The original soundtrack was composed by Graeme Revell and featured the Dead Can Dance singer Lisa Gerrard. The score was rejected by Michael Crichton and was replaced by one composed by Crichton's usual collaborator, Jerry Goldsmith.