Princess Diana, Sarah Ferguson Had A 'Highly Competitive' Relationship, Royal Biographer Says

Princess Diana and Sarah Ferguson had a highly competitive relationship, according to a royal biographer.

The late Princess of Wales and Duchess of Cornwall were very close before their fall out. In fact, many were convinced that Princess Diana and Ferguson were best friends. However, their friendship was complicated.

According to royal biographer Allan Starkie in his book "Fergie: Downfall of the Duchess," "Diana's relationship with the Duchess fluctuated quite a bit."

"For the majority of the time, the relationship was highly competitive," Starkie added. "They were fighting an ongoing battle through use of their charities, and using the press as a weapon. They would look, like actresses on opening night, at the reviews of their latest charity trips."

Starkie added that Princess Diana and Ferguson "compare them and whine if the other got better reviews." Author David Leigh also shared an anecdote about the People' Princess and Duchess of York.

"Sarah promoted an AIDS charity, and Diana rang her up and said ‘What on Earth do you think you’re doing, trying to hijack a cause that I’ve done so much for?’" he said. Princess Diana reportedly "slammed the phone down" after that call.

Ferguson reached out to Princess Diana and faxed her a message that read "I'm sorry, I didn't mean to offend you." "Because of that silly little incident, they didn’t speak for weeks," Leigh added.

According to the book "Diana's Nightmare - The Family," there was a time when Ferguson plotted a tale revenge to Princess Diana by trying to land the cover of Harper's Bazaar after Vogue successfully featured Princess Diana. The duchess reportedly wanted to choose a photographer and demanded if the magazine's choice "matched up to Demarchelier's credentials." Chris Hutchins and Peter Thompsons were convinced that Ferguson's "motive was obvious - she wanted to outshine Diana."

Judy Wade had a different take about Princess Diana and Ferguson's love and hate relationship. According to her, it's normal between two women with a close bond who are like sisters to have a row.

"Sisters occasionally row and fall out, and that's what happened to them," Wade explained.

Ferguson admitted that she and Princess Diana haven't talked until the latter's fatal accident. Ferguson said that she tried to "support and protect her [Princess Diana] as I would a younger sister—as I still do today, as a best friend."

She also recalled how Princess Diana could easily make her laugh. "Diana was one of the quickest wits I knew; nobody made me laugh like she did," Ferguson added.