Susan Sarandon on 'breaking royal protocol' when meeting Queen Elizabeth: 'Still don't know what I did wrong'

Susan Sarandon has opened up about her brush with royalty in a new documentary.

The Hollywood A-lister was panned at the time for "breaking royal protocol" when she met Queen Elizabeth at a polo match in Windsor in 2018.

The actress said it was all a jumble because she wasn't expecting Her Majesty to be seated and had been given conflicting advice.

READ MORE: Royal throwback shared to mark birthday

The New York-based star attended the Royal Windsor Cup at Guards Polo Club with her youngest son, Miles Robbins, who had been invited to DJ after the match.

Before she could meet any of the royals, her friends gave her some conflicting advice, the actress explains in documentary Portrait of the Queen.

READ MORE: Detail faked in photos from Prince George's christening

"[When] I got to to England and my friends were like, 'do not bow, whatever you do don't bow, that is so passe'," Sarandon said.

"You know, there's this push and pull about whether and how much respect you're going to give to the royal family and whatever. They said to me 'don't bow. Do not bow' and I thought, 'well, I'm going to be respectful'."

The big day arrived and Sarandon said Her Majesty enjoyed lunch in a separate section, while there was a spare seat next to the actress for the monarch, which sat empty.

Royal aides in the meantime gave the actress a briefing.

"They said: 'Don't ask her any questions. [If] she talks to you, it's okay but don't ask her anything. And this is what you have to do, you know, bow when she comes'," Sarandon recalls.

"So I'm all stressed out, I think, 'am I going to bow or am I not going to bow?'

"So anyway, the moment came when they finally said: 'Okay, it's your turn to meet the Queen'. And here is what happened - she was sitting down!

"So of course, I had to bend over to shake her hand and so it looked like a curtsy. So, at the end of the day, I kind of did bow and the headlines still said after all of that, that I had gone against protocol somehow. I still don't know what I did wrong."

According to the British press, the moment the then 71-year-old actress broke protocol was when she initiated a handshake with Her Majesty, then 92.

The actress recalls that she went quite during the meeting with the Queen, as she remembered the earlier briefing from royal aides.

READ MORE: Artist reveals rare honour led to iconic image of Queen Elizabeth

"She was lovely to me," Sarandon says.

"I don't think we had a very long conversation. I think it was kind of just 'Oh, it's so nice to meet you'. And, and I said 'it's so nice to meet you'. And I remembered that you can't ask her anything.

"So that definitely puts a damper on your conversation because she has to be in charge of everything."

The documentary Portrait of The Queen is in selected cinemas across Australia from March 18.