Prince William and Kate Middleton
Photo: Getty

Even the best and strongest couples have their share of problems. For Prince William and Kate Middleton, most of those problems happened early in their relationship, when Will was infamously on the fence about staying with Kate.

Before their well-known 2007 breakup, the couple took a brief “trial separation” in 2004, during their final year at St. Andrews University, where they first met while both attending school.

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Express reports that royal author Katie Nicholl, wrote about the mini-split in her 2010 book, William and Harry. According to Nicholl, Will knew he wanted to take a break from the relationship and planned a boys-only yachting holiday in Greece as a chance to spend some time away from Kate.

“Kate was beginning to question William’s commitment to their relationship, and she also had her own creeping doubts about their future after St. Andrews,” Nicholl wrote, according to Express.

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So, why was Kate questioning the relationship? According to Nicholl:

“A number of things had caused her to question William’s commitment, although she had not raised them with him yet. One was William’s friendship with an American heiress called Anna Sloan.”

Apparently, Will and Anna had a lot in common and Kate was worried that their connection might include some romantic feelings, at least on Will’s part. Express quotes Nicholl as writing:

“Anna had lost her father, businessman George Sloan, in a tragic shooting accident on the family’s 360-acre estate in Nashville, and she and William had bonded over the loss of their parents. When Anna invited William and a group of friends to Texas for a holiday before he went to Greece, it hurt Kate deeply. She suspected William might have feelings for the 22-year-old heiress.”

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Nicholl reports that nothing romantic ever happened between Will and Anna, who eventually married Eddie Smith and attended Will and Kate’s wedding as a guest.

“Anna was not the least bit romantically interested in William, and the friendship was never anything more than just that,” Nicholl wrote.

This article originally appeared on Marie Claire.