Did Prince Philip Have an Affair with a Russian Ballerina?

Spoilers ahead!

Season 2 of The Crown wastes no time delving into the tensions in Queen Elizabeth and Prince Philip's marriage by the mid-1950s. Episode 1 centers around an implied affair between Philip and a world-famous dancer.

Ahead of Philip's five-month tour aboard the Royal Yacht Britannia, the Queen hides a gift in her husband's briefcase and stumbles upon a photo of a beautiful ballerina — Galina Ulanova. At the time, she doesn't confront Philip about the photograph, but later on the episode, she attends a performance of Ulanova in Giselle, and the two women knowingly eye one another several times from across the stage.

Although Ulanova was a real dancer — the Russian-born dancer was known as one of the greatest ballerinas of the 20th century and performed the lead roles in Swan Lake, Romeo and Juliet and Giselle — there is no evidence of a real-life affair between Ulanova and Prince Philip.

"People have often said, 'He must have been unfaithful,' but there is no solid evidence for that," Robert Lacey, the show's historical consultant, told PEOPLE. "When you've seen the episodes, you get the feeling why people make that supposition. But there is no evidence for it."

Ulanova was indeed touring in Britain during the time depicted in the show. The celebrated dancer, who was 46 at the time (16 years older than Elizabeth), was fawned over by the press during her visit. She died in 1998 in Moscow at the age of 88.

"The Queen is depicted as suspecting, or believing, that something is wrong without being able to prove it," Lacey continued. "And it provokes the worst period in their relationship without transgressing the bounds of what is proven."

Elizabeth and Philip: A Royal Romance — The Real-Life Story Behind The Crown is available now.

What the affair storyline does do, however, is set up the royal couple's resolve to keep their marriage strong despite its challenges.

"The show reflects that they did something about it," said Lacey, author of The Crown: The Official Companion. "You see how they created a new relationship, which leads to the second batch of children [Andrew and Edward]."

As for Philip's long absence abroad, it "was very much Elizabeth's idea — to test out the royal yacht, to represent her at the Olympics, to open the Olympic Games [in Australia]," Lacey said. "It wasn't him skulking off on his own, but Elizabeth's idea to give him the challenge."

Show creator Peter Morgan said he wanted to depict the strains the royal marriage goes under on season 2.

"People are complicated, and I want to write a marriage in all its complexities, but at the same time, I think it's a triumphant marriage," Morgan told PEOPLE at the show's London premiere. "They're still married — and are happily married."

Morgan continued, "She has always been nuts about him. She was nuts about him from the moment she met him, and I think that shows."

• With reporting by Simon Perry