Who wrote the English ballad "La Belle Dame sans Merci" ?

“La Belle Dame Sans Merci” is a ballad ,one of the oldest poetic forms in English. Keats uses a stanza of three iambic tetrameter lines with the fourth dimetric line which makes the stanza seem a self-contained unit, giving the ballad a deliberate and slow movement, and is pleasing to the ear. Keats uses a number of the stylistic characteristics of the ballad, such as the simplicity of the language, repetition, and absence of details.Keats's economical manner of telling a story in "La Belle Dame sans Merci" is the direct opposite of his lavish manner in "The Eve of St. Agnes". Part of the fascination exerted by the poem comes from Keats' use of understatement.

In keeping with the ballad tradition, Keats does not identify his questioner, or the knight, or the destructively beautiful lady. What Keats does not include in his poem contributes as much to it in arousing the reader's imagination as what he puts into it. La belle dame sans merci, the beautiful lady without pity, is a femme fatale who attracts lovers only to destroy them by her supernatural powers. She destroys because it is her nature to destroy. Keats could have found patterns for his "faery's child" in folk mythology, classical literature, Renaissance poetry, or the medieval ballad. With a few skillful touches, he creates a woman who is at once beautiful, erotically attractive, fascinating, and deadly of being with whom one cares for when they are from different social classes.