LONDON (Reuters) - Terry Pratchett, the British author of the popular "Discworld" series of fantasy novels, has died of a form of Alzheimer's disease at the age of 66, his publishing house said on Thursday.
Pratchett died at home surrounded by his family with his cat sleeping on his bed, Transworld Publishers said.
"In over 70 books, Terry enriched the planet like few before him," said Larry Finlay, managing director at Transworld, a division of Penguin Random House.
"As all who read him know, Discworld was his vehicle to satirize this world. He did so brilliantly, with great skill, enormous humor and constant invention," he said.
The author, who sold tens of millions of books worldwide, was diagnosed with posterior cortical atrophy (PCA), a progressive degenerative condition, in 2007.
He had continued to write, completing his last book, a new Discworld novel, in the summer of 2014 before succumbing to the final stages of the disease.
Pratchett had become a high-profile campaigner for the legalization of assisted death.
"I would like to die peacefully with Thomas Tallis on my iPod before the disease takes me over and I hope that will not be for quite some time to come, because if I knew that I could die at any time I wanted, then suddenly every day would be as precious as a million pounds," he said in a lecture in 2010.
"If I knew that I could die, I would live. My life, my death, my choice."
(Reporting by Estelle Shirbon; editing by Michael Holden)