The problem of recording movements of the human body is almost as old as the art of dancing: it has been said that the ancient Egyptians had a system of notation, but there is no real evidence to prove that this was so. The present system was developed by the Russian dancer Vladimir Ivanovich Stepanov at the end of the 19th century. It is based on existing music notation, and although basic is certainly practical: one has only to read the official testimonial, signed by such people as Petipa and Johanssen, to realise this. Lessons in the system were given at the Imperial Ballet Schools, and many ballets of the period were notated in it. Stepanov's book is no more than a skeleton key, showing the general principles of his system and their application, yet even as it stands it can be used to decipher old notations - it was by means of notations made in Stepanov's system that Nicolai Sergeyev was able to reproduce The Sleeping Princess for Diaghilev, and other ballets for the Sadler's Wells Ballet and International Ballet. More recently, other hands have used the system to revive ballets long thought to have been irrevocably lost.