She’d been warned to dress conservatively, but Marilyn Monroe didn’t listen. Instead, when invited to meet Queen Elizabeth II during her 1956 stay in London, the movie star donned a glamorous gold lamé spaghetti-strap gown. At the Empire Theatre, a nervous Marilyn took the queen’s offered hand and curtsied. The women, both 30, even enjoyed a little small talk. “She asked how I liked living in Windsor, and I said, ‘What?!'” recalled Marilyn, who was in England to film The Prince and the Showgirl. “She said that as I was staying in Englefield Green, near to Windsor, we were neighbors.”

Elizabeth hadn’t been as excited as her sister, Princess Margaret, to meet Marilyn, but the actress’ rare combination of beauty and humility enchanted her. “Elizabeth expected Marilyn to be one of those boisterous, overly confident celebrities, and was pleasantly surprised to find the opposite,” says a royals insider. “The queen has a strong intuition and immediately got a sense of the little girl lost in Marilyn.”

Marilyn Monroe and Queen Elizabeth's Connection: Pair Wrote Each Other

The gracious monarch didn’t even blink at the actress’ lowcut gown. “It wasn’t her style, but she’s not one to judge others, especially if they’re not family members,” says the insider. “She said Marilyn looked dazzling that evening.”

They would never see each other in person again, but they’d always look back at that night fondly. “Afterward, Elizabeth watched all of Marilyn’s movies — sometimes with Prince Philip. She’d joke that the Duke of Edinburgh had a crush on Marilyn, and I think he did a little,” says the insider. “And not many people know this, but Elizabeth and Marilyn kept in touch and would write to each other.”

Marilyn also felt that they’d made a real connection. “The queen is very warmhearted,” Marilyn said. “She radiates sweetness.”