Prince Harry may be preparing for a high-profile return to Britain, but one royal relationship appears to be damaged beyond repair.

The Duke of Sussex is expected to travel from California to the UK next month with Meghan Markle for an Invictus Games event in Birmingham. However, palace insiders say Queen Camilla has not forgotten the vicious attacks Harry made against her in his explosive memoir, Spare.

Four words in particular are said to have pushed their already tense relationship past the point of no return.

Harry described Camilla as a “villain,” “dangerous” and a “wicked stepmother,” while also accusing her of leaking private information to the press to improve her own public image.

According to royal sources, the words “wicked stepmother” cut especially deep and permanently changed the way Camilla views her stepson.

“For the queen, those lines were a red line,” one longtime royal source claimed. “They weren’t just criticism. They felt like a permanent stain on her character.”

The source added that Camilla believes some family disputes can be repaired with an apology, but publicly painting her as a villain is something that cannot easily be undone.

“It seems like Harry has now poisoned his relationship with Camilla forever,” the insider said.

Harry’s upcoming visit is expected to mark the launch of the one-year countdown to the 2027 Invictus Games in Birmingham.

The Sussexes may also bring their children, Prince Archie, 7, and Princess Lilibet, 5. It would be the children’s first visit to Britain in four years.

King Charles is reportedly determined to see his grandchildren despite the years of public attacks, television interviews and damaging allegations that have torn the royal family apart.

Reports suggest the king has even offered Harry and Meghan royal accommodations at Buckingham Palace during their stay.

One palace aide said Charles is putting his role as a father and grandfather ahead of his anger.

“The king’s view is that he is a father and a grandfather before anything else,” the aide claimed. “He wants to see his son and his grandchildren while he still can.”

However, Charles’ apparent attempt to make peace is not being welcomed by everyone inside the royal family.

Relations between Harry and Prince William are said to remain “cold as ever,” while Princess Catherine is also believed to be deeply hurt by the claims made in Spare.

Harry wrote that William and Catherine encouraged him to wear a Nazi uniform to a costume party in 2005.

According to Harry, he asked the couple what he should wear and claimed they both replied, “Nazi uniform!”

The costume sparked a major scandal after photographs of Harry wearing it were published.

Harry also accused William of pointing his finger at Meghan during a heated argument, prompting her to allegedly tell him, “Keep your finger out of my face!”

In another explosive claim, Harry said William physically attacked him during a confrontation over Meghan and knocked him to the floor.

A friend of William and Catherine claimed the couple believes Harry sacrificed them to make his book more shocking and profitable.

“They feel they were thrown under the bus to make the book more explosive,” the source said. “That is a wound that hasn’t healed.”

The insider warned that Harry and Meghan spending a few days in Britain will not suddenly repair years of bitterness.

“They will be polite if a meeting happens, but no one is pretending this is a happy reunion,” the source said.

King Charles was also heavily criticized in Harry’s memoir.

Harry wrote that his father was “not cut out for single parenting” after the death of Princess Diana in 1997.

Those comments reportedly devastated Charles, but sources say the king has made a deliberate decision not to allow his anger to prevent a possible reconciliation with his youngest son.

“Charles knows what was written,” one palace aide said. “But he has decided that holding on to bitterness is a luxury he does not have at this stage of his life.”

It remains unclear whether Harry and Meghan will meet with Camilla, William or Catherine during their visit.

Royal observers believe any encounter would be carefully controlled and kept as private as possible.

One former courtier said senior royals will certainly not be rushing to welcome the Sussexes back with open arms.

“The senior royal contingent will not be lining up at the airport to greet them,” the source said.

But with Harry and Meghan returning to Britain and the world’s cameras expected to follow their every move, palace aides are already bracing for another royal media circus.