Jack the Giant Killer is a 1962 United Artists fantasy film starring Kerwin Mathews in a fairy tale story about a young man who defends a princess against a sorcerers giants and demons.
In the Duchy of Cornwall of fairy tale days, the malevolent sorcerer Pendragon, ruler of giants, witches and all creatures evil, was defeated by the wizard, Herla, and along with his disciples exiled to an uncharted, unknown island. Pendragon however vows revenge and Herla dies, meaning there is no longer a threat against Pendragon. Years later the kingdom celebrates the crowning of Princess Elaine Judi Meredith. The reception goes well until Pendragon Torin Thatcher arrives disguised as a foreign lord. He gives her a magic toy that is actually Cormoran the giant, and which is given to the Princess. When Elaine is asleep, Pendragon uses his magic to make the giant grow to full size and capture Elaine. The castle guards are too late to stop the giant. Cormoran takes Elaine to a ship, but before it can sail a brave farm lad named Jack Kerwin Mathews rescues Elaine. Jack then fights the giant and kills it. In gratitude, King Mark Dayton Lummis makes Jack her protector and entrusts him to safely guide her to a convent across the sea. However he does not know that Elaines waitingmaid, Lady Constance Anna Lee, is a witch in league with Pendragon and reveals the Kings plan to him.Enraged at having his plan fouled, Pendragon makes up another one, determined to stop Jack. While Jack and Elaine are planning their trip, Mark and his servants discuss the potential danger that is now Pendragon. While Jack and Elaine are rejoicing at sea, Pendragon sends his demonic witches to intercept Jacks ship. Elaine is captured, while Jack and his friend Peter Roger Mobley are cast overboard. At Pendragons castle, Pendragon uses his powers to turn Elaine into an attractive but evil witch. Pendragon then returns to Cornwall and confronts King Mark, telling him he has one week to renounce the throne and let Elaine rule alongside Pendragon, or she will die. After he vanishes, Mark realizes Constance has betrayed him, and when she stands before a mirror, she appears as a witch. The King breaks
Source: Wikipedia