Terry Pratchett: A Life With Footnotes by Rob Wilkins review - An official biography leaves the inner life untouched

Terry Pratchett, aka Sir Terence David John Pratchett OBE (1948 - 2015), now has an official biographer in Rob Wilkins, the custodian of Pratchett's literary estate, who worked with Pratchett for 20 years, 15 as his personal assistant.

Pratchett, who progressed, in Wilkins' words, "from a kid from a Council house to a knighthood and a mansion near Salisbury by the sheer power of his imagination alone", is one of the most popular British authors of all time, with 100 million books sold in 37 languages. Forty-one of Pratchett's 50 books were set on his famous Discworld, "world and mirror of worlds", a platform which allowed him to satirise society through inventive plots, laced with memorable, especially female, characters.

Pratchett in later life suffered from what he called "The Embuggerance", a rare form of Alzheimer's. Wilkins became almost a carer, "an emergency pop-up Pratchett" in the words of Pratchett's daughter, Rhianna. When Pratchett lost the ability to type, Wilkins helped edit his AI dictation and spoke for Pratchett at events, including the numerous honorary doctorates that Pratchett was awarded. Pratchett ended up with 10 honorary doctorates, including ones from Trinity College Dublin and the University of South Australia. Pratchett took pleasure, on occasion, in calling himself Dr Dr Dr Dr Dr Dr Dr Dr Dr Dr Pratchett.

Pratchett always intended to write an autobiography but only left behind "rough hewn, disjointed" segments which ended in 1979, before his publishing career really took off. Wilkins, while noting they were an invaluable source, observes that Pratchett was not always "an entirely reliable documenter of his own life".

Wilkins is a faithful and comprehensive documenter of Pratchett's life in 430 pages but ones which never really reveal the inner Pratchett. The reader instead is given a lot of what Pratchett called the business of being "a nauthor". So, instead of an analysis of Pratchett's creative processes, or the social and political beliefs that underpinned the novels, we get instead extensive detail of publishing deals, book sales, book tours (very important in the Pratchett pantheon), the numerous film, TV and audio adaptations and the ever-expanding Discworld merchandise.

I interviewed Pratchett six times for The Canberra Times, with the last time in Sydney near the end of his life, when he was accompanied by Wilkins, but he always kept his family life private. In a biography, however, we need more than the bland occasional descriptions of family life.

Pratchett, aged 20, married his first girlfriend, art student Lyn Purves, in 1968 and their only child Rhianna was born in 1976. In the early 1970s, Pratchett said that he and Lyn were "hippies with a wage", although it wasn't a large wage, from Pratchett's provincial journalism. They cultivated a large vegetable garden and allotment, with goats, chickens, goats, bees and lots of home brewing.

Rhianna, who became an author and video-game creator, recalls her father being more of a "big brother" while her mother "was the disciplinarian". Wilkins quotes Rhianna reflecting, at the age of nine or 10, that her father was always very busy, but there is no extrapolation of this comment nor are there details of Rhianna's life as a teenager. Similarly, Lyn almost disappears from the book after the 1970s yet she surely played a crucial part in assisting and facilitating Pratchett's success.

Pratchett's family life couldn't have been perpetually idyllic, given Pratchett's rigorous work schedule and renowned temper. Wilkins recalled being summoned on more than one Boxing Day to Pratchett's house, so that Pratchett could escape what he called "all this family shit" for "a little light work". Pratchett's great friend Neil Gaiman, the co-author of Good Omens, recognised that Pratchett was not simply the " jolly old elf" of PR creation.

Wilkins experienced Pratchett's "anger in all the 57 varieties" but he doesn't document many of them. Mark Barrows, in The Magic of Terry Pratchett (White Owl, 2020) - a solid biography, but written by someone who never met Pratchett - quotes Wilkins, stating in 2017, that he had an argument every day with Pratchett: "every day I quit, every day Terry sacked me". Yet the relationship undoubtedly worked.

Pratchett may have become a workaholic because of the influence of his mother, "the formidable and dominant" Eileen, who was no admirer of his fiction. Wilkins notes she perhaps only became a proud mother when Pratchett was knighted in 2009, although recording that Eileen was disappointed that she personally wasn't presented to the Queen!

Pratchett fans will revel in the detail of Terry Pratchett: A Life With Footnotes, but it doesn't uncover the inner Pratchett nor explore the creative foundations of his undoubted literary genius. Wilkins is at his best, and most original, in his moving and sensitive account of Pratchett confronting the increasing physical and mental impact of dementia in the years from 2008 to his death.

Terry Pratchett wrote in Reaper Man (1991), "no one is finally dead until the ripples they cause in the world die". The ripples from Pratchett's books will live long and certainly continue to prosper long into the twenty-first century.