Prince Valiant is a 1954 adventure film based on the Prince Valiant comic strip by Hal Foster.
The story begins with the forced exile of the Christian royal family of the Viking kingdom of Scandia - King Aguar, his wife, and his son Prince Valiant - by the Viking rebels led by the usurper Sligon.
During his wanderings, Valiant witnesses a clandestine meeting between a group of Sligon's Vikings and a black-clad knight. During his flight, Valiant runs into Gawain, and after becoming convinced that Valiant is indeed the son of Aguar and hearing the prince's story of the mysterious Black Knight, who is not unknown to the knights of Camelot, Gawain takes Valiant to his king. Valiant is accepted by the king as a prospective knight. Sir Brack, takes an extraordinary interest in Valiant and offers to train him, but Valiant is instead assigned to Gawain.
Some time later, Sir Brack offers to take Valiant to the place where the young prince has seen the Black Knight in order to backtrack the mysterious figure. They separate, but Valiant is ambushed by a group of bowmen and barely escapes with his life and an arrow in his back. Wounded, he stumbles into the territory of King Luke and is taken in by his daughters, Aleta and Valiant fall in love, but King Luke disapproves of Valiant's Viking origin and so their relationship must remain a secret for the time being.
Valiant returns to Camelot and discovers that Gawain had tried to find him and run into an ambush by the Black Knight as well, likewise having escaped within an inch of his life. Noting that Sir Brack had temporarily disappeared around the same time, Valiant becomes suspicious, but on the advice of Gawain, suppresses his suspicion of Brack. Some time later, Aleta and Ilene come to Camelot to attend a tournament held in their honor; as an added prize, the winner of this joust will win Aleta's hand. Valiant dons the armor of Gawain, who is too seriously wounded to participate, in order to win Aleta, but he fails and is unmasked. But then another contender appears and wins the bout before falling off his horse - and this knight turns out to be Sir Gawain himself. Awakening on his sickbed, Gawain beholds Aleta and falls head over heels in love with her, and out of respect for his patron, Valiant does not dare tell him the truth.
For his act of presumption, Valiant is punished to being confined to his quarters and attending to his master. But then a mysterious messenger comes to the castle to see Sir Brack, and the same night King Aguar's seal is thrown through the window of Sir Gawain's chambers and lands at Valiant's feet. Realizing that his parents are in trouble, Valiant immediately leaves Camelot. He is ambushed and captured by Sligon's Vikings and the Black Knight, who reveals himself as Sir Brack. Brack has made a pact with Sligon: For delivering King Aguar's family, Sligon will assist Brack in conquering Camelot and assuming rulership over Britain.
Aleta arrives at the scene and is captured herself, and the two are brought to Thule, where Sligon prepares their execution. However, a group of Christian Vikings led by Aguar and Valiant's old friend Boltar infiltrates the castle. Valiant is discovered before Boltar manages to kill Sligon, and during his struggle with a guard a false signal is given which makes the Christian Vikings attack too early. Just as things seem bleak, Valiant sets fire to the castle, throwing the defenders into confusion, and eventually slays Sligon in single combat.
Valiant returns to Camelot and accuses Brack of treachery. Brack calls for a judicial duel to the death, and despite Gawain's protests and his offer to fight in Valiant's stead, the young prince accepts the challenge and succeeds in killing the traitor with his father's sword after a long and hard fight. In the end, Valiant is finally made a fully privileged Knight of the Round Table.
- James Mason as Sir Brack
- Janet Leigh as Princess Aleta
- Robert Wagner as Prince Valiant
- Debra Paget as Ilene
- Sterling Hayden as Sir Gawain
- Donald Crisp as King Aguar
- Brian Aherne as King Arthur
- Primo Carnera as Sligon
Brian Ahern would later play King Arthur again in Sword of Lancelot