In a lecture delivered in February 2010, a little more than two years after Terry Pratchett announced he had been diagnosed with posterior cortical atrophy, a rare form of Alzheimer’s disease, the fantasy author described the way he preferred to die. “I would live my life as ever to the full and die, ­before the disease mounted its last ­attack, in my own home, in a chair on the lawn, with a brandy in my hand to wash down whatever modern ­version of the ‘Brompton cocktail’ some ­helpful medic could supply. And with ­Thomas Tallis on my iPod, I would shake hands with Death.”

Pratchett’s vision didn’t quite come to pass, though he did, in the end, die at home, as he desired.

The beloved author of some 70 books succumbed to his disease at the age of 66. Larry Finlay, managing director of Pratchett’s publisher, Transworld, is quoted in the Guardian as saying the author died “with his cat sleeping on his bed, surrounded by his family.”

Best known for his Discworld series of fantasy novels, Pratchett was knighted in 2009. Over the course of his career he amassed a fiercely devoted following, which only seemed to increase with each successive book. “All who read him know,” says Finlay, “Discworld was his vehicle to satirise this world: he did so brilliantly, with great skill, enormous humour, and constant invention.” The penultimate book in the series appeared in 2013; the 41st and final volume, entitled The Shepherd’s Crown, is due to be published later this year.

Following his diagnosis, Pratchett became an outspoken advocate for the right to a medically “assisted death,” a term he preferred to “assisted suicide.”

“I have reached the ­conclusion that a person may make a decision to die because the balance of their mind is level, realistic, pragmatic, stoic, and sharp,” he said in 2010. “And that is why I dislike the term ‘assisted suicide’ applied to the carefully thought-out and weighed-up process of having one’s life ended by gentle medical means.” In a 2012 appearance at the Hay Festival, Pratchett said that what scared him was not dying, but dying badly. He followed up with a typically caustic Pratchettian witticism: “I can’t be bothered about death. I have made him so popular that he owes me one.”

The author was known for his sharp sense of humour, but friend and fellow writer Neil Gaiman – with whom Pratchett co-authored Good Omens, a comic novel about the apocalypse – warned not to discount the anger that lay just below the surface. “The anger is always there, an engine that drives,” Gaiman wrote in 2014. “And that anger, it seems to me, is about Terry’s underlying sense of what is fair and what is not. It is that sense of fairness that underlies Terry’s work and his writing, and it’s what drove him from school to journalism to the press office of the SouthWestern Electricity Board to the position of being one of the best-loved and bestselling writers in the world.”

On his own site, Gaiman pays tribute to Pratchett, saying in part, “There was nobody like him. I was fortunate to have written a book with him, when we were younger, which taught me so much.”

Pratchett’s official Twitter feed announced the death poignantly, by alluding to the author’s body of work. The final tweet reads simply, “The End.”