Hill created a story of a dog named Spot in 1976 for his son Christopher. In that first book, Spot was hiding behind little flaps which could be lifted by small children, an innovation which he devised. Hill said that he aimed to recognise "that children have far more intelligence and style than many adults credit them with", and to invite them to experience "ideas which were just outside their experience yet were basic enough to be understood." After a friend introduced him to a
literary agent, his first book ''
Where's Spot?'' was published in 1980 by
Frederick Warne & Co and quickly became popular. He then produced a series of similar books and expanded the range of characters. His books are estimated to have sold more than 60 million copies. The stories were translated into 60 languages, and led to a series of
animated stories for television as well as
merchandise. ==References==