She is noted for numerous series of books based on recurring characters and designed for different age groups. Her books have enjoyed huge success in many parts of the world, and have sold over 600 million copies.
One of Blyton’s most widely known characters is Noddy, intended for early years readers. However, her main work is the genre of young readers’ novels in which children have their own adventures with minimal adult help. Series of this type include the Famous Five (21 novels, 1942–1963, based on four children and their dog), the Five Find-Outers and Dog, (15 novels, 1943–1961, where five children regularly outwit the local police) as well as The Secret Seven (15 novels, 1949–1963, a society of seven children who solve various mysteries).