BESTSELLING AUTHOR SIR Terry Pratchett has passed away at the age of 66, his publisher Transworld Publishers has announced.

In a statement, the publishing house confirmed that the fantasy author passed away at home today surrounded by his family. The author had been suffering from Alzheimer’s Disease.

The British author was best known for his Discworld series, which have sold over 85 million copies worldwide. He held the distinction of being the second-most read author in the UK.

Transworld described Pratchett as one of the “brighest, sharpest minds” the world had ever known.

In over 70 books, Terry enriched the planet like few before him. As all who read him know, Discworld was his vehicle to satirize this world: he did so brilliantly, with great skill, enormous humour and constant invention.

Prolific and popular, the writer was awarded a knighthood in 2009 for his services to literature and even joined the staff of Trinity College as an adjunct Professor in the School of English in 2010.

Pratchett was diagnosed with Alzheimer’s Disease in 2007 and later became an advocate and campaigner for dementia research.

Last year, he wrote a piece for The Guardian in support of the Dementia Friends campaign in which he implored people to help those in their community who may be suffering from dementia.

There are hundreds of thousands of us out there living with dementia who – to paraphrase the song in the advert – every now and again really could do with a little help from a friend.

Unfortunately, the author succumbed to the disease today. His death was confirmed via a series of heartbreaking tweets this afternoon.

Pratchett is survived by his wife and daughter.