Prince George's recent solo appearance with parents Prince William and Kate Middleton marked his most formal royal duty to date.

The 12-year-old future King took on his first royal duty by attending a Buckingham Palace tea honoring World War II veterans, and it gives us a glimpse of the future leader he is becoming.

Dressed in a dark suit with a blue tie, the prince asked the vets extremely thoughtful questions, "Did you use any U-boats?" and "How many flight missions were you on?" according to PEOPLE.

"This was the first sign of George taking on future duties," Russell Myers of The Mirror tells PEOPLE.

"That is quite a responsibility to sit down and chat with veterans like that. It was incredible," a palace insider shared.

For the looky-loos, this moment highlighted how both William and Kate have been carefully preparing their eldest son for the throne one day in his future.

"It's a slow game and it gets him used to it on the couple's terms rather than anybody else's," says the palace insider.