This movie definitely has some positive attributes, but also some annoying flaws.
It is visually enjoyable, with very nice cinematography and superb costume design. And there is some fine acting, especially by Richard Burton, as well as John Gielgud.
But there are many historical inaccuracies, most of them entirely unnecessary to the story.
For example, Henry may have been harsh with his sons and with his wife, but was kind to his mother Matilda, who had always been very loving and devoted to him. The lack of respect between the two added nothing to the movie.
Thomas Becket was not a Saxon, he was born in London but was the son of a couple from Normandy. Henry was less Norman than Becket, he was the son of an Angevin father, and his mother was a mix of Norman, Scottish, and Anglo-Saxon royalty. Her grandparents were William I, Matilda of Flanders, Margaret of Wessex (a descendant of Alfred the Great, she became St Margaret of Scotland), and Malcolm Canmore, King of Scotland. So Henry II had more Anglo-Saxon heritage (1/8) than Thomas Becket (none).
The conflict between Henry and Becket actually went on for years, and there were many differences between them, not just the decision to execute a priest.
Henry was almost certainly not a homosexual. He considered Becket a good friend and supporter at one time, but the movie makes him out to be madly in love with Becket while having no liking or respect for anyone else.
The actress who played Eleanor of Aquitaine was nothing like her. In reality, Eleanor was an elegant and exceptionally strong woman. The makers of The Lion in Winter made a wiser choice by casting Katharine Hepburn.
