According to royal expert Robert Jobson, Prince William is not the easiest person to work with: in his latest book, Our King: The Man and the Monarch Revealed quotes a senior royal official.

"He is a driven man, which sometimes makes him impatient," the source said of the Prince of Wales.

Compared to his son, William's father, Prince Charles, is more patient: "When dealing with Prince Charles, William can have a temper. The boss [Prince Charles] also has a temper, but it doesn't last forever. He gets frustrated and explodes, but he forgets about it in an instant. With William, he seldom forgets."

Jobson, who is also William's biographer and published William at 40: The Making of a Modern Monarch last year, writes that Prince Charles is "shocked by his sons' sometimes violent temper, which reminds him of his late mother Princess Diana's anger and his own mother, Princess Diana," he wrote, according to Page Six.

"He knew they were both strong-willed and even stubborn. Managing conflict is very difficult and can be detrimental to the monarchy itself," Jobson wrote. At one point, Prince Charles was shocked by his sons' belligerence."

Prince Harry wrote of spare William's temper tantrums, including a physical altercation and another conversation that "got so heated" that Prince Charles had to intervene. According to Harry, Prince Charles pleaded with his sons not to "make his last years unhappy."