
Sir Terence David John Pratchett (28 April 1948 – 12 March 2015) was an English humorist, satirist, and author of fantasy novels, especially comical works. He is best known for his Discworld series of 41 novels. In December 2007, Pratchett announced that he had been diagnosed with early-onset Alzheimer's disease. He later made a substantial public donation to the Alzheimer's Research Trust, filmed a television programme chronicling his experiences with the condition for the BBC, and became a patron for Alzheimer's Research UK. Pratchett died on 12 March 2015, aged 66.