Prince Harry’s memoir, Spare, has finally officially gone on sale after a week of revelations following the early release of the book in Spain. The book contained a number of bombshell anecdotes about Prince Harry’s personal life and allegations against a number of members of the Royal family. Nonetheless, the memoir quickly became the fastest selling non-fiction book ever, with around 400,000 hardback, e-book and audio format copies bought in its first day.