King Charles—known as Prince Charles when he was married to his first wife, Princess Diana— wasn’t prone to romantic overtures,

the late Princess of Wales’ former butler Paul Burrell said.

Speaking to Marie Claire, Burrell said that Diana, who died at age 36 in an August 31, 1997 car accident in Paris,

would “send romantic cards to Prince Charles,” but those acts of love weren’t reciprocated.

“It’s such a sad thing to say that he never loved her, and so he never returned the compliment,”

Burrell told the outlet. “He wasn’t romantic. He tried to be, but he didn’t have a romantic bone in his body.”

That said, there were some moments of real tenderness between the couple, who married on July 29, 1981, separated in 1992, and finalized their divorce on August 28, 1996, just 368 days before her death. (The King eventually went on to remarry the former Camilla Parker Bowles—now Queen Camilla—in 2005, who he was also involved with during his marriage to Diana.)

Speaking to biographer Andrew Morton for his bombshell 1992 book Diana: Her True Story, Diana told Morton that Charles sent her a special letter and a gift the night before their wedding. “He sent me a very nice signet ring the night before to Clarence House, with the Prince of Wales feathers on and a very nice card that said, ‘I’m so proud of you, and when you come up I’ll be there at the altar for you tomorrow,'” Diana said.

“Just look ‘em in the eye and knock ‘em dead,” the letter concluded.

Diana was seen wearing the aforementioned signet ring several times, and Charles still wears his own signet ring regularly. Interestingly, their daughter-in-law Meghan Markle debuted a signet ring of her own with her and husband Prince Harry’s royal cypher while at the Invictus Games in Canada earlier this month.

Though the gift and letter were surely welcome arrivals, Diana admitted that she “had a very bad fit of bulimia” the night before her wedding, but the actual morning of the wedding, she said she felt “deathly calm.”

Though she told Morton she was “so in love” with Charles, “I felt I was a lamb to the slaughter,” she added. “I knew it and couldn’t do anything about it.”

Yet, she continued, “I just absolutely thought I was the luckiest girl in the world. He was going to look after me. Well, I was wrong on that assumption.”