The Duke and Duchess of Sussex were not invited to Barack Obama's lavish 60th birthday party as they pay their respects to the queen, a royal biographer claims.

Speaking to The Sun, Angela Levin, a royal expert and author of "Harry: Biography of a Prince," claims that the former first family didn't send Prince Harry and Meghan Markle an invitation because they wanted to take a "step back" out of respect for Queen Elizabeth II.

Levin added that the Obamas could only handle "one brother and his wife" at a time, and they couldn't invite both because of the ongoing rift between the royal family members. If Obama could pick from one of the brothers, he will "go towards William."

In addition, as reported by Daily Mail UK, Meghan Markle is "desperate" to be included on Obama's guest list. Levin stated that she wanted to be the "special guest," but the former first family didn't invite her and the prince in the first place.

Other Reasons Why Prince Harry, Meghan Markle Weren't Invited

Per early reports, Camilla Tominey, another royal expert, claims that the Obamas didn't like how the Duke and Duchess of Sussex treated the Royal family.

In an article published by the Telegraph, Obama and his wife firmly believe in the phrase "blood is thicker than water," and they would put their families first regardless of the situation. Allegedly they think that the prince doesn't have the same principle as them.

The Obamas also allegedly disliked how Prince Harry attacks his family, especially his past interview with Oprah Winfrey, a documentary titled "The Me You Can't See," and an episode of the "Armchair Expert Podcast," to which he exposed the Royal family during those appearances.

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Before the report, another expert, Dicki Arbiter, suggests that Prince Harry and Markle were not among the "double A-lister" personalities despite moving into the United States. It means they are not as wealthy as Oprah Winfrey, Rihanna, and more.

Daniela Elser also believes that the royal couple isn't in the same league as other famous personalities; what they're known for today is their rift with other royal family members.

Barack Obama's Lavish 60th Birthday In $11.75 Million Martha's Vineyard

Obama initially had more than 500 guests for his birthday, but the former first family scaled it down due to CDC guidelines. Levin believes that Prince Harry and Meghan Markle weren't included in both guestlists.

Markle's friend Gayle King was present in the event with Chrissy Teigen, Beyonce, Erykah Badu, and more.

The event caused significant controversy as the attendees were not wearing facemasks despite the highly contractive Delta variant of the Coronavirus.

READ ALSO: Real Reason Why Prince Harry, Meghan Markle Weren't Invited To Obama's Birthday Proves One Thing About the Royals: Report