King Charles' Sweet Private Nickname for Princess Kate Revealed as Royal Author Lifts Lid on Their Close Bond

LONDON — King Charles III and Catherine, Princess of Wales, may look formal at state banquets and royal engagements, but in private they are said to share a warm relationship that includes affectionate nicknames.

According to royal author Robert Jobson, the 77-year-old monarch refers to his daughter-in-law as "beloved" or "darling." The Express reported this week that Kate, 44, is believed to call Charles "Grandpa" in private, a nod to his role in the lives of her three children.

The claims come from Jobson's biography "Catherine, Princess of Wales." Jobson wrote that the king regularly greets William's wife with a kiss and enjoys trading jokes with her away from public view.

Buckingham Palace does not typically comment on books or reports about the royal family's private lives, and it has not confirmed the nicknames.

A relationship spanning more than two decades

Charles and Kate have known each other for more than 23 years, since she began dating Prince William when both were students at the University of St Andrews in Scotland.

She was formally introduced to Charles, then the Prince of Wales, after the relationship became serious. Her first visit to Balmoral Castle, the royal family's Scottish estate, came around 2003.

William and Kate married at Westminster Abbey in 2011. They have three children: Prince George, Princess Charlotte and Prince Louis.

Over the years, the relationship between the king and his daughter-in-law has become one of the most closely watched in the royal family, especially as Kate's public role has grown.

'A good influence on the entire family'

Jobson's book quotes a palace courtier who says Charles values the part Kate plays within the royal household.

The insider told Jobson that the king knows Kate "is a good influence on the entire family."

"He loves and truly appreciates everything she does," the courtier said.

Kate has long been seen as one of the most popular members of the royal family. Since William became heir to the throne after Queen Elizabeth II's death in September 2022, the couple have taken on a larger share of royal duties.

Peacemaker role

Kate has also been described as a calming presence in the family at a time of well-publicized tensions.

Radar Online reported that an insider called her "somebody who always tries to see both sides of any dispute." The same source described her as a "stabilizing influence" within the family.

She has been credited in several royal accounts with helping smooth relations between Charles and William, acting as what has been called an "instinctive peacemaker."

The royal family has faced strained relationships in recent years, most notably with Prince Harry, who stepped back from royal duties with his wife, Meghan, in 2020 and moved to California.

Bond deepened by cancer

The relationship between the king and the princess is thought to have become especially meaningful after both were diagnosed with cancer within weeks of each other in early 2024.

Buckingham Palace announced in February 2024 that Charles had been diagnosed with an undisclosed form of cancer. It was discovered during tests that followed a procedure for an enlarged prostate the month before. The king began regular treatment and briefly stepped back from public-facing duties.

In March 2024, Kate revealed her own diagnosis in a personal video message. She said cancer had been found after major abdominal surgery and that she had begun a course of preventive chemotherapy.

She completed chemotherapy in September 2024 and announced in January 2025 that she was in remission. She has since gradually returned to full royal duties.

Charles has continued to work through his treatment. In December 2025, he said in a televised address that his treatment schedule could be reduced in the new year "thanks to early diagnosis, effective intervention and adherence to doctors' orders." He called the development "good news."

Both royals have used their experiences to encourage people to seek early diagnosis and support cancer charities.

Public displays of affection

While the royal family rarely shows emotion in public, Charles and Kate have shared warm moments at events in recent years. Royal watchers have frequently pointed to friendly exchanges between them at state occasions, church services and family gatherings.

Charles has also given Kate significant formal roles. In 2024, he named her a Royal Companion of the Order of the Companions of Honour. The award recognizes people who have made a major contribution to the arts, science, medicine or government. She was the first person to receive the newly created royal companion designation.

Kate continues to focus on her signature causes, including early childhood development, mental health and the outdoors. She has also become a more prominent figure at state visits and national events alongside William, the future king.

Behind palace walls

Accounts of private nicknames and family warmth offer a rare glimpse of life behind palace walls, where the royal family has long guarded its personal relationships.

Jobson, 62, is a longtime royal correspondent and has written several books about the British monarchy. His biography of Kate draws on interviews and palace sources, though many of the accounts in it, including the nicknames, have not been independently verified.

Whatever names they use in private, the portrait from those close to the family is consistent: a king who values his daughter-in-law, and a princess who has become one of the steadiest figures in the House of Windsor.