The evil Wizard Saruman the White was one of the most pivotal characters in The Lord of the Rings. Both J. R. R. Tolkien's novel and Peter Jackson's film adaptations introduced Saruman as a wise and trustworthy figure. However, when Gandalf traveled to Isengard to seek his aid, he learned that his old friend had given in to the evil influence of the Dark Lord Sauron. From that point onward, Saruman became the secondary antagonist of the story, threatening Middle-earth just as his master did.
Source：https://www.cbr.com/lotr-saruman-villain-timeline/
