Prince Harry’s upcoming book promises to be ‘controversial’, and the rift that has grown between him and Prince William ‘is unlikely to be healed by this book’, a royal commentator has said. Richard Fitzwilliams suggested that the Duke of Sussex may write that he feels ‘overshadowed’ by his brother and heir to the throne.The Duke’s highly-anticipated memoirs were announced as being titled Spare, the publisher revealed today.Penguin Random House released details of the book, including the front cover and formats in which it will be made available when it is published on January 10 next year.Markus Dohle, the publishing house’s chief executive, said it was ‘honoured’ to be publishing the Duke’s ‘candid and emotionally powerful story’.He revealed: ‘[Prince Harry] shares a remarkably moving personal journey from trauma to healing, one that speaks to the power of love and will inspire and encourage millions of people around the world.’READ MORE: Prince Harry ‘full of resentment’ as expert attacks new book title Fitzwilliams suggested that the Duke of Sussex may write that he feels ‘overshadowed’ (Image: Richard Fitzwilliam/Penguin Random House) Penguin Random House released details of the book, including the front cover (Image: Penguin Random House)’As a future Queen, it was sometimes said, Diana’s duty was to produce an ‘heir and a spare’.’The book’s title announcement came alongside the launch of a dedicated website, where Sussex fans can pre-order their copy.Referencing the now-famous image of a young William and Harry walking behind their mother’s coffin, it said: ‘It was one of the most searing images of the twentieth century: two young boys, two princes, walking behind their mother’s coffin as the world watched in sorrow – and horror.’As Diana, Princess of Wales, was laid to rest, billions wondered what the princes must be thinking and feeling – and how their lives would play out from that point on.DON’T MISSRishi Sunak urged to ‘frack now, compensate later’ as PM back tracks [INSIGHT]Sunak sets sights on joining £8.4TRN trade bonanza after call with Aus [ANALYSIS]David Lammy breaks into hysterics as he reflects on Truss as PM [VIDEO] Fitzwilliams: ‘It is ‘raw’ and ‘unflinching’, and this means controversial’ (Image: TalkTV) ‘As Diana was laid to rest, billions wondered what the princes must be thinking and feeling’ (Image: Getty)’It is ‘raw’ and ‘unflinching’, and this means controversial.’He added: ‘The rift between the brothers is unlikely to be healed by this book; did he, we will wonder, feel overshadowed as the title suggests?’He will probably give interviews and there will undoubtedly be serialisations and probably a good deal of controversy. With a title like this, the Palace will be very worried.’As the Duke of Sussex has previously stated, the proceeds from the book will be donated to charities Sentebale – which helps those in Lesotho and Botswana with HIV and Aids – as well as WellChild, of which Prince Harry has been a royal patron for fifteen years.