Expert: King Charles' Trooping the Colour appearance showcases his resilience in the face of his cancer battle.

For King Charles III, the show must go on.

The British monarch, who has been diagnosed with an undisclosed form of cancer, will be attending Trooping the Colour on Saturday. This is the second time he will be attending the event, and it will be the first time since his diagnosis was made public by Buckingham Palace.

"According to Christopher Andersen, author of "The King," Queen Elizabeth used to say, "I must be seen to be believed," which meant she had to publicly demonstrate the health and progress of the monarchy and the country. This symbolized the unity and stability of the nation."

"Andersen stated, "The king's job now is to show up and make it seem like everything is okay within the House of Windsor, as King Charles is fighting cancer.""

The tradition of the monarch having two birthday celebrations, one for their actual birthday and another for public festivities, originated during the reign of King Charles II, who ruled from 1660 to 1685. Trooping the Colour was established as an annual event during the reign of King George III, who ruled from 1760 to 1820.

This year's festivities will be different as Charles will attend the event while undergoing cancer treatment. Instead of riding on horseback, he will be seated in a horse-drawn carriage alongside Queen Camilla.

"Andersen stated that he desperately wished to be out on horseback to convey that everything was going smoothly and not to worry, but his doctors had informed him that he couldn't do it this year. As a result, he wouldn't be able to convey the message in the way he wanted to."

Andersen emphasized the importance of the king, 75, showcasing the monarchy's strength, especially now. Kate Middleton, the daughter-in-law, confirmed on Friday that she will attend the parade, marking her first public appearance since her cancer diagnosis.

A Buckingham Palace spokesperson stated that His Majesty is thrilled that the princess will be attending tomorrow's events and eagerly anticipates the entire day, as reported by People magazine.

The king was resolved to adhere to his late mother's advice: remain composed and persevere.

Andersen stated that he understands the symbolism of the moment and recognizes the challenges faced by the monarchy. The royal family is currently facing a major issue with both the king's cancer diagnosis and the Princess of Wales' cancer diagnosis.

"Prince Andrew's Jeffrey Epstein scandal forced him to withdraw from public life, while Prince Harry and Meghan Markle have been sidelined in their relationship with the royal family. The lack of progress between Harry and his brother and father has left the king struggling to maintain his position."

"Andersen stated, "I believe he must demonstrate to the public that everything is fine, and the balcony scene is crucial. In the final scene, the entire royal family is present on the balcony during the flyover.""

The royal's alleged mannerisms, which have raised eyebrows over the years, are unlikely to be seen by the public in the king's book.

"Andersen chuckled, saying, "This monarch is one of the quirkiest we've ever had. He still travels with his childhood teddy bear, which only his nanny could mend. It's a bit of a mess at this stage. I write about all of his preferences, such as the silverware having to be at a certain angle, his valet laying out his clothes in a certain way, and him traveling with his own chef.""

"Andersen claimed that the individual in question possesses a comfortable upholstered white leather toilet seat that he takes with him wherever he goes. He also brings his own hand towels and toilet paper. However, during Trooping the Colour, a formal ceremonial event held to honor the military, it is unlikely that such items will be visible. The primary purpose of the event is to showcase the country's impressive vintage jets and cutting-edge aviation technology."

Behind the scenes, there will be a lot of silly things happening, Andersen stated.

The king wants the celebration to emphasize the monarchy's future, rather than the ongoing health struggles in the palace. Charles has long desired a more streamlined monarchy, and his reign has been closely watched.

Andersen stated that he had specific plans to remove certain members of the royal family from the payroll because he believed there were too many people the crown was supporting and it was confusing. He intended to focus on a core group.

"Unfortunately, he couldn't have predicted that Harry and Meghan would depart, but that Andrew would create a scandal for him. Andrew's relationship with Jeffrey Epstein made it impossible for him to continue as a working royal. As a result, Charles was left with a very small group."

"The Princess of Wales, who is the most popular member of the royal family and represents the future of the royal family, is seriously ill, according to Andersen. Prince Edward and his wife, Sophie, are stepping up to help, but it's a difficult time for Charles."

As the Trooping the Colour marks a joyous occasion for the royal family and Britons, Andersen predicts that Charles will take a different approach to his reign while undergoing treatment.

Andersen claimed that Charles is the kind of person who has a spectacular temper, but he seemed to be keeping it under control. Perhaps facing the issue of mortality for the first time, which he hadn't expected, might have contributed to this.

"Irony abounds. After spending your entire life pursuing a role, you find yourself in it for only two years before being told you must fight for your life. No one could have predicted this outcome. However, he has displayed immense bravery and resilience in the face of adversity."

The Associated Press contributed to this report.