The term luohan or arhat is used to designate the original disciples of Sakyamuni Buddha. As holy persons who have conquered all passions, they came to be popularly worshipped. Groups of luohans ranging in number from 16 to 100, are depicted in Chinese art from the Tang Dynasty up to recent times. Sixteen luohans are first mentioned in the Six Dynasties period, later the number is increased to eighteen. They are usually treated as a form of portraiture in which individual features and personality traits are highlighted.