“My father will be King so you better watch out” Prince George, 9, told his classmates

Prince George knows he will one day be king and made this known in a cheeky comeback to a classmate who crossed him, a royal expert has claimed.

The eldest son of Prince William and Kate Middleton told his schoolmate that his father would be King and that they “better watch out”, according to royal author Katie Nicholl.

In her book The New Royals, Nicholl claimed George, 9, and his siblings, Princess Charlotte, 7, and Prince Louis, 4, were being raised with an understanding of the monarchy and a “sense of duty”.

She added that while George has been told he will one day be monarch, the Prince and Princess of Wales are trying not to weigh him down with too much responsibilities too soon.

Nicholl wrote: “They are raising their children, particularly Prince George, with an awareness of who he is and the role he will inherit, but they are keen not to weigh them down with a sense of duty.

“George understands he will one day be king and as a little boy sparred with friends at school, outdoing his peers with the killer line: ‘My dad will be king so you better watch out’.”