British fantasy writer Terry Pratchett has passed away today after a years-long battle with Alzheimer’s disease.

Revealing his illness in 2007, the author — who had a strong following among fans of fantasy fiction — said he had been diagnosed with “a very rare form of early onset Alzheimer’s,” which he described as “an embuggerance.”

He said then, “Frankly, I would prefer it if people kept things cheerful, because I think there’s time for at least a few more books yet.”