eunuch [Gr.,=keeper of the couch], castrated human male, particularly a chamberlain of a harem in Asia. The custom of employing eunuchs as servants in wealthy or royal households is very ancient; it reached its epitome at the court of Constantinople under the Byzantine emperors, from whom the Ottoman sultans adopted it. Eunuchs often rose to high position, the Byzantine general Narses being the most celebrated example. In the Muslim world the use of eunuchs was far less common than is generally believed; however, the sale of young males to be eunuchs was formerly an important element in African trade. The castrating operation, which retards the development of normal male characteristics, including the deepening of the voice, was performed with varying thoroughness and with varying success. From Constantinople spread the custom of using eunuchs in choirs. In the opera seria (see opera) of the 18th cent. the male heroes' roles were sung by castrati, and the papal choir used castrati until the beginning of the 19th cent. A famous castrato was Carlo Broschi Farinelli.