While viewers get a quick debriefing on all of Diana's alleged affairs thanks to Anne's chat with the Queen, viewers only meet Captain James Hewitt (played by Daniel Donskoy) in episode nine.
The pair allegedly met in 1986 when Hewitt served as her horseback riding instructor and went on to have a five-year romance, which was more intense than depicted in The Crown.
"Hewitt, a natural womanizer, gave her the attention and affection she relished, and then the passion she yearned for," Ken Wharfe, her former bodyguard, wrote in his book, Diana: Closely Guarded Secret.
Diana confirmed the affair during a BBC1 Panorama programme in 1995, saying, "I adored him. I was in love with him, but I was very let down."
Hewitt, who later participated as a paid source for Anna Pasternak's bombshell 1994 book, Princess in Love, opened up about their relationship in a 2017 interview on Sunday Night. "It's a gradual period and then, you know, suddenly you can't get enough of each other or see each other as much as you want," he explained.
He also went on to deny allegations that he is Prince Harry's real father. "No, I'm not," he answered when asked the question point-blank, going on to explain the rumor persisted for decades because it "sells papers."
"It's worse for him probably, poor chap," Hewitt added of Prince Harry.