Kate and William helping son George grasp the idea of becoming the future king

Prince William and Kate Middleton are already preparing their eldest son Prince George for his future role as the king of England.

Royal historian and writer Robert Lacey writes in his updated edition of Battle of Brothers, that the Duke and Duchess of Cambridge had put in quite a lot of thought into how they will explain the idea of becoming monarch to their firstborn.

"William has not revealed to the world how and when he broke the big news to his son. Maybe one day George will tell us the story himself. But sometime around the boy's seventh birthday in the summer of 2020 it is thought that his parents went into more detail about what the little prince's life of future royal 'service and duty' would particularly involve," Lacey wrote.

“William's aim as a father, the prince stressed, was to give his son 'a normal family upbringing,' enabling the monarchy 'to stay relevant and keep up with modern times,” he went on to say.

Moreover, royal expert Katie Nicholl explained in a chat with OK! how William and Kate are gradually explaining the entire system to their children.

"They make a point of ensuring their three children feel equal and that they’re all treated the same," she said.