Beatrix Potter conceived her tale of Peter Rabbit on 4 September 1893 in an illustrated letter to Noel Moore, the five-year-old son of her friend and former governess, Annie Moore. Noel was recovering from a bout of scarlet fever so Beatrix amused him with a story based upon her real pet rabbit, Peter Piper: 'I don't know what to write to you, so I shall tell you a story about four little rabbits, whose names were - Flopsy, Mopsy, Cottontail, and Peter…'.

In the following years Beatrix sent other picture letters to Noel and to his brother and sisters, including stories about an ‘excessively impertinent’ squirrel called Nutkin and a disconsolate frog called Mr. Jeremy Fisher. In 1900 Annie suggested to Beatrix that her picture letters might contain material for several picture books. Fortunately the children had kept their letters safe and Beatrix was able to borrow them to copy and rework her text and illustrations. Noel’s story of Peter Rabbit was to become Beatrix’s first book.