The cardiac surgeon was a big part of the late princess' life in the years prior to her death.
The late Princess of Wales entertained several relationships after leaving the future king and prior to her 1997 death. One lesser-known but seemingly more serious romance was between Diana and cardiac surgeon Hasnat Khan. Actor Humayun Saeed is portaying the U.K.-based doctor in the Netflix series.
Diana and Khan privately dated for two years, though the world is more familiar with her romance with Dodi al-Fayed, with whom she died in a car crash in Paris, France, in 1997 after 30 days of dating.
Here's everything you need to know about the man Diana once referred to as "Mr. Wonderful."
How They Met
Diana met Khan in 1995, two months before her infamous Panorama interview, at the Royal Brompton Hospital in London. The Pakistani-born doctor specialized in heart and lung surgery. They crossed paths at the hospital while Diana was visiting a friend who was recovering from heart surgery. Diana took to making regular unaccompanied visits to the hospital to meet with sick and recovering patients as well as meet with Khan in secret.
"I found her a very normal person. We all have our drawbacks, but I found her a very normal person with great qualities, and some personal drawbacks, like bad habits. We all have drawbacks," Khan said in his only personal interview with The Mail on Sunday in 2008. "I think she did great work for the country and for people all over the world – not just in the U.K. but everywhere. I think that is important."
The pair dated from 1995 to 1997 and went to great lengths to keep their romance private. They'd often meet at Diana's Kensington Palace residence with Khan smuggled in the trunk of Diana's butler, Paul Burrell's, car.
She would leave messages for him under the name Dr. Armani and would wear wigs to trick photographers and members of the public when they went out on dates.
She would also stay with Khan's uncle, Professor Jawad Sawid Khan, who owned a home in Stratford upon Avon.
The couple talked about their potential future together, despite their many differences and difficulties. Diana visited Pakistan multiple times while in her relationship with Khan. She even privately met with Khan's family in Lahore, and was said to be considering the idea of permanently moving to Pakistan so they could continue their romance.
"I think it definitely was [a special moment] for my family, and I think she enjoyed the afternoon tea with them," Khan shared with the Mail on Sunday in 2008.
Khan was also privately introduced to Diana's children, Prince William and Prince Harry, and even reportedly studied the Koran every night as she considered converting to be with Khan.
In a 2008 inquest into Diana's death, Khan shed light on some of the problems in his relationship with Diana.
"I knew I would not be able to lead a normal life," he said in a statement at the time. "My main concern about us getting married was that my life would be hell because of who she was."
The heart surgeon was also concerned that if they were to ever have children together that they too would not be able to "do normal things."
Khan noted that he told Diana that the only way they'd be able to lead a normal life would be in his home country of Pakistan, a notion she entertained but ultimately decided against.
New information on the relationship between Diana and Khan surfaced in 2008 when he gave a personal statement for the inquest into her death. Khan shared that after Diana returned from a holiday in the south of France aboard Mohamed al-Fayed's yacht in the summer of 1997, "Diana told me it was all over between us."
The late Princess of Wales had connected with Mohamed's son, Dodi al-Fayed, on the trip and believed he “could give her all the things I could not. He had money and could provide the necessary security for her."
Dodi died alongside Diana shortly after in a car accident in Paris, France.
Life After Diana
Khan went on to marry Hadia Sher Ali in 2006. They later divorced. He relocated to Pakistan, but denies that the move was due to negative press surrounding his past romance with Diana.
"If I was going to leave the U.K. because of this, I would have left in 1997, not now," he told The Mail on Sunday in 2008.