The Perry Index is a widely used index of "Aesop's Fables" or "Aesopica", the fables credited to Aesop, the story-teller who lived in ancient Greece between 620 and 560 BC. Modern scholarship takes the view that Aesop probably did not compose all of the fables attributed to him; indeed, a few are known to have first been used before Aesop lived, while the first record we have of many others is from well over a millennium after his time. Traditionally, Aesop's fables were arranged alphabetically, which is not helpful to the reader. Perry and Rodriguez Adardos separated the Greek fables from the Latin ones, with the Greek ones first; then they arranged each group chronologically and by source; finally they arranged the fables alphabetically within these groups. This system also does not help the casual reader, but is the best for scholarly purposes.