They were brought up in a Yorkshire vicarage and wrote books which were best-sellers in Victorian times
They invented their own little kingdom, which they wrote about in a domestic magazine.
They were plagued by ill-health and died relatively young. But the Gattys of Ecclesfield, near Sheffield, especially two of them, Margaret and her daughter Juliana Ewing, were world-famous in their day.
Lord Baden-Powell named The Brownies after the little people in one of Juliana's books and Margaret had a marine worm named after her.
Clare Jenkins has been talking to the authors of a book about the Gattys, Mel and Joan Jones, at St Mary's Church in Ecclesfield, where this remarkable family lived.
The BBC is not responsible for the content of external websites.