Reports from Terry Pratchett's publisher reveal that the popular fantasy author and creator of the "Discworld" book series passed away at 66 after fighting off Alzheimers for years.

The Guardian reports that "[Pratchett] passed away in his home, with his cat sleeping on his bed surrounded by his family on Thursday."

His death was first reported after Pratchett's Twitter account @terryandrob posted "Terry took Death's arm and followed him through the doors and on to the black desert under the endless night".

Pratchett's publisher Larry Finlay confirmed his death in a statement released to the public, saying he was "deeply saddened to learn that Sir Terry Pratchett has died. The world has lost one of its brightest, sharpest minds......As all who read him know, Discworld has his vehicle to satirize this world: he did so brilliantly, with great skill, enormous humor and constant invention."

Pratchett's Discworld was renowned by millions of readers. Pratchett's work in fiction earned him the title Officer of the Order of the British Empire in 1998. Pratchett was knighted during the 2009 New York Honours. Sky One reported that "[Pratchett] is the second most-read writer in the UK, and seventh most-read non-US author in the US."

Pratchett wrote over 70 novels, 40 of which were about  "Discworld". The first volume of the Discworld series, titled "The Color of Magic," was published in 1983 and has been adapted into graphic novel, radio and television. Pratchett's last novel, "The Long Mars," was published in Summer 2014.