Michelangelo's reputation as a sculptor was established early and has rarely been questioned. Until the 20th century he was commonly regarded as the most important sculptor of the modern era. His work is idiosyncratic, of exceptional expressive power and of strikingly limited range. It consists in the main of monumental marble statuary. He sometimes worked in media other than marble to oblige friends or especially powerful patrons, but he encouraged the identification of his sculpture with stone.