Queen Elizabeth’s marriage to Prince Philip is one of the most enduring marriages in royal history. They have been together for more than 70 years now, with four children and several grandkids. However, a peek into the inside story of their marriage will reveal that just like other marriages, theirs is also haunted by rumors of infidelities.

Throughout their union, the Duke of Edinburgh has been linked to several women, one of which was stage actress Pat Kirkwood, whose legs used to be called “the eighth wonder of the world.” Prince Philip allegedly had an affair with this showgirl between the 1930s and 1940s, secretly meeting her on various occasions.

Prince Philip met Kirkwood for the first time in London, when he went into her dressing room before a performance. The prince allegedly fell in love with Kirkwood at first sight, so he immediately invited her to dinner and danced with her until dawn. That time, Queen Elizabeth was eight months pregnant with their firstborn, Prince Charles.

When reports about their illicit affair broke, Queen Elizabeth was reportedly down in the dumps. But just as expected, Prince Philip denied the rumors. Kirkwood also never admitted having an affair with the prince until her death in 2007.

It has been decades since Prince Philip was rumored to have a secret affair with Kirkwood, but it reportedly continues to haunt his marriage to Queen Elizabeth. In 2012, royal biographer and historian Michael Thornton revealed that he had custody of the love letters between Prince Philip and Kirkwood, but he would not show it to anyone because he made a promise to Kirkwood that he would not spill the beans. The royal biographer, however, said he would hand the letters to Prince Philip’s chosen biographer once he dies.

Kirkwood is not the only woman that Prince Philip allegedly had an affair with. Years ago, he was also linked to actresses Helene Cordet, Merle Oberon and Anna Massey. It remains unknown how these rumors of extramarital affairs have taken their toll on Prince Philip’s relationship with Queen Elizabeth.

But if there’s one thing that royal fans can be sure of, however, it is the fact that none of these women have ever really rocked the royal household. Queen Elizabeth and Prince Philip are now more than seven decades strong in their marriage and are enjoying their golden years together.

Queen Elizabeth and Prince Philip Queen Elizabeth II, Prince Philip, Duke of Edinburgh, make their way in the royal procession during day 1 of Royal Ascot at Ascot Racecourse. Charlie Crowhurst/Getty Images for Ascot Racecourse