There’s only person who can determine whether or not Kate Middleton and Meghan Markle will have Princess titles. The Duchess of Cambridge and Duchess of Sussex are pictured attending Christmas Day church services at Church of St Mary Magdalene in Sandringham, King’s Lynn, England on Dec. 25, 2018. Stephen Pond/Getty Images

It’s been reported that Camilla Parker-Bowles is the reason Meghan Markle and Kate Middleton do not carry Princess titles. However, the Duchess of Cornwall isn’t the one who decided what titles Prince William and Prince Harry’s wives would have.

According to royal expert Victoria Arbiter, though Camilla did defer from taking the official title of Princess of Wales out of respect for Princess Diana when she married Prince Charles in 2005, only Queen Elizabeth had the ability to determine if Kate and Meghan would have a title, or what their titles would even be.

“Had the Queen not conferred wedding day dukedoms on William and Harry, their wives would have been known as Princess William of Wales and Princess Henry of Wales in the same way Baroness Marie Christine von Reibnitz became Princess Michael of Kent upon her 1978 marriage to Prince Michael,” she wrote (via Express UK). “Any changes are solely at the Queen’s discretion—not Camilla’s.”

“Camilla, Catherine, Meghan and indeed the rest of the Royal Family’s stylings are steeped in centuries of royal history. The only person able to implement revisions or bestow titles is the sovereign,” she added. “Should the Queen choose to do either, her decrees are based on a number of factors including changes that have been made to existing royal rules, long-standing tradition and the examples set by kings and queens who have gone before her.”

That royal tradition means that should dukedoms not have been given to Princes William and Harry on their wedding days and they solely kept their titles as Princes, their wives would have to take their first names with their princess titles, as only blood-born princesses can use the title with their own first name. Princesses Beatrice and Eugenie, as well William’s daughter Charlotte, are examples of the royals who can keep those titles.

In addition, Arbiter noted that Princess Diana’s title was incorrect over the years because it did not follow the tradition either.

“She became HRH The Princess of Wales when she married Charles, but ‘Princess Diana’ was deemed far catchier,” she said. “Today she is still affectionately known as Princess Diana, even though her title changed once again following her divorce.”