Royal biographer Penny Junor: Princes William and Harry are so dependent on one another
Penny's book Prince William:
Born To Be King is out now and it's clear Wills and Harry, 28, have a deep bond.
'[William] a very interesting character,' says Penny, 62.
'But there is quite a lot of Harry in my William book because it's hard to talk about them separately - they are so close and so dependent on one another.'
Penny reveals that Wills, 29, agreed to be interviewed when he found out she was writing about him - but he changed his mind.
'He hates talking about himself,' says Penny.
'However, he did allow senior members of his household to speak with me.'