Excalibur | I think I downloaded the wrong movie

The film Excalibur is a legendary epic fantasy film that tells the mythology of King Arthur and his magical sword. Assisted by the mysterious wizard Merlin, Arthur successfully pulls the sword Excalibur from the stone and unites the entire Kingdom of England. Together with the Knights of the Round Table, he builds the golden age of Camelot, before ultimately being betrayed by his own sister, Morgana. The betrayal storyline in this movie is truly beyond my comprehension as a movie lover.😅