When Lady Diana (†36) died twenty-one years ago, Prince Harry and Prince William's world was shattered. However, their happy family life was already on thin ice thanks to the break down of their parents' marriage. 

The new documentary William and Harry: Brothers in Arms shows just how the princes reacted to the news that their parents were separating.  

Prince William and Prince Harry reacted very differently to the news  

The documentary reveals that Lady Diana drove to William and Harry's boarding school, so as to be the first to break the news to them. The princes reacted to the news very differently. Prince William accepted remained stoic an calm, simply saying, "if you’re happier, if you’re going to be a happier mummy, then this is the right thing to do".

Prince Harry did not take the news nearly as well and was anything but calm. These two reactions aren't all that surprising when one considers that William was older and already knew that his parents were not getting along. 

As Lady Diana's former butler Paul Burrell revealed in his book A Royal Duty that Prince William made his mother a touching promise before she died. When Diana was upset at having to give up her title upon divorcing Charles, William comforted her, saying "Don’t worry, Mummy. I will give it back to you one day when I am King".