popularity is soaring following his marriage to Kate Middleton and the birth of their child, Prince George.
1. Fidel Castro - £3,500 ($5,732)
Following the death of Nelson Mandela in 2013, Fidel Castro is now the world's most valuable living signer. Castro's divisive nature and importance to 20th century history ensure there are many suitors for his elusive autograph.
All figures taken from the PFC40 Autograph Index and refer to signed photos.