To the world Queen Elizabeth is a global leader whose reign spans 12 American presidents and six Popes.
To Prince William, she's 'my incredible grandma.'
An upcoming book previewed in Britain's Daily Mail paints the portrait of a close personal relationship between William and the Queen.
In it the Prince recalls the time royal advisers handed him his wedding guest list.
I was given this official list of 777 names - dignitaries, governors, all sorts of people - and not one person I knew.'
He said he looked at it in horror and said there was only one person he could go to: the boss.
'I rang her up the next day and said: "Do we need to be doing this?" And she said: "No. Start with your friends first and then go from there." And she told me to bin the list.
Not to say she doesn't pull rank on the Prince, too.
As an officer in a multitude of service branches he had a choice of which military uniform to wear at the wedding.
Except he didn't. The Queen insisted he wed in his Irish Guards uniform - one of her own regiments.
You don't always get what you want, put it that way,' So you just do as you're told!'
The Prince says he is in no rush to even think about HIS turn as head of state.
William is reportedly interested in extending his tour of duty with Britain’s royal air force past 2013.
Palace officials say that will ultimately be a decision for William and his grandmother – when the time comes.
Prince William says he and his brother Harry have also advised the Queen at times…like when they taught her how to text and use a cell phone.