First Knight (1995) on Netflix

After King Arthur of Camelot has fought several wars which has led to peace and justice for his land, he is turning his attention to thoughts of marriage, his chosen one being Lady Guinevere, who has become head of neighboring Leonesse following the death of her father. Peace and justice for Arthur and Guinevere are short lived as Prince Malagant, one of the knights of the round table, wants Camelot for himself and King Arthur deposed. Many in the land follow Malagant, whose quest also involves marauding Leonesse. As the King's betrothed, Guinevere becomes Malagant's target in achieving both his goals. Meanwhile, Lancelot is a free-living peasant who often makes his way through life by demonstrations of his sword fighting prowess. His skill is largely due to his ability to assess his opponents, and not fear dying. On Malagant's first attempt at abducting Guinevere, Lancelot, by happenstance, is there to save her. He falls in love with her at first sight. Although attracted to the man who saved her, Guinevere cannot think of any other man in the lead up to her marriage to Arthur. Because of his attraction to Guinevere, Lancelot becomes involved in the battles between Malagant and Arthur in Lancelot doing whatever needed to keep Guinevere safe. As these battles brew and as Arthur becomes indebted to Lancelot for saving Guinevere at the possible expense of his own life, Guinevere cannot help but fall for Lancelot, resulting in a romantic triangle comprised of Arthur, Guinevere and Lancelot, a triangle of which Arthur is unaware.