The sci-fi writer passed away on 12 March (15) after a long battle with Alzheimer's disease, and his publishers have now announced Pratchett's last novel was finished prior to the tragedy and is set to hit shelves in September (15).

The Shepherd's Crown will be the 41st installment in the author's hugely popular Discworld series, which has sold more than 80 million books worldwide since its launch in 1983.

Tom Weldon of publishing company Penguin Random House says, "It is a huge privilege to be publishing Sir Terry Pratchett's final Discworld novel, The Shepherd's Crown. Terry's writing is loved and respected the world over and this publication will be an incredibly important and special event for us all at Penguin Random House, and for fans and readers everywhere."