Nut crackers in the form of wooden carvings of a soldier, knight, king, or other profession have existed since at least the 15th century. These nutcrackers portray a person with a large mouth which the operator opens by lifting a lever in the back of the figurine. Originally one could insert a nut in the big-toothed mouth, press down and thereby crack the nut. Modern nutcrackers in this style serve mostly for decoration, mainly at Christmas time. The ballet The Nutcracker derives its name from this festive holiday decoration. The ballet Nutcracker is a two-act ballet, originally choreographed by Marius Petipa and Lev Ivanov with a score by Pyotr Ilyich Tchaikovsky. The libretto is adapted from E.T.A. Hoffmann's story "The Nutcracker and the Mouse King". It was given its premiere at the Mariinsky Theatre in St. Petersburg on 18 December 1892, on a double-bill with Tchaikovsky's opera, Iolanta.