St Catherine’s Monastery is renowned for its art treasures. Its collection of more than 2000 icons is probably the largest in the world. Its library of 4500 ancient Christian manuscripts is second only to that of the Vatican Library in Rome. The monastery’s isolation saved its oldest icons during the 8th century when the Byzantine emperor Leo III ordered the destruction of any imagery depicting Jesus or one of the saints. These early icons are naturalistic and free from stylisation and the rules that later icons followed.