Michael Morpurgo's very poignant and moving book 'War Horse', currently being made in to a film directed by Steven Spielberg, started life as a stage production at the National Theatre on the Southbank in London
http://en.wikipedia.org/wiki/War_Horse_(film))
http://www.independent.co.uk/arts-en...e-2004779.html
http://www.imdb.com/title/tt1568911/