Prince Harry's attendance at King Charles III's coronation next month may prove to be a difficult experience, particularly without the support of his wife, Meghan Markle, according to royal expert Dr. Tessa Dunlop.

Historian, writer, and broadcaster Dr. Dunlop spoke with Us Weekly about her predictions for the Duke of Sussex's experience during the May 6 ceremony in London. She is currently promoting her new book, "Elizabeth & Philip: A Story of Young Love, Marriage and Monarchy," released earlier this month.

Dr. Dunlop described the upcoming coronation as "a bit of a nightmare" for Prince Harry, highlighting his visible stress during his last public appearance with the royal family at Queen Elizabeth II's funeral last year. She observed his discomfort as he helped Meghan into the car after the funeral, and noted that this time, he will be without Meghan's support.

The historian speculated that Prince Harry, who often leans on Meghan during joint engagements, could struggle without her presence. She explained that the couple bonded over their shared difficult childhoods and found solace in each other. As Prince Harry attends the coronation alone, Dr. Dunlop believes he will feel exposed and demoted, potentially sitting further away from the royals.

Prior to the announcement that Meghan would not attend the coronation, Dr. Dunlop claimed that the royals were worried about providing security for her, as the couple lost access to their security detail after stepping back from royal duties in 2020. The expert argued that the potential public reaction to Meghan's presence could have painted Britain in a negative light, with protection costs running high.

Buckingham Palace confirmed on April 12 that Prince Harry would be present at King Charles' coronation, while Meghan and their two children, Archie and Lilibet, remain in California. Various theories have emerged regarding Meghan's decision not to accompany Prince Harry to the event.

Omid Scobie, royal correspondent and co-author of "Finding Freedom," tweeted that Archie's birthday, coinciding with the coronation, influenced the couple's choice. However, GB News host Dan Wootton proposed that Meghan opted out due to concerns about being booed by the public. Richard Eden, Daily Mail Diary editor and broadcaster, speculated on "Palace Confidential" that the Sussexes' unmet demand for an apology from the royal family contributed to Meghan's absence.