This venture marks a change of direction after their forays into documentary-making, and both of them publishing books.
It will form part of their deal withNetflix, worth a reported $100million.
The books publisher, Penguin Random House, previously published Harrys memoirSpare.
Prince Harry and Meghan MarkleMike Coppola/Getty Images
It is Fortunes second novel.
HarrysHeart of Invictusdocumentary is also set for release this month.
