" In the West, castrati are known to history not for their political influence but mainly for their vocal peculiarities. In addition to removing the power to procreate, the castrating operation retards the deepening of the voice, and leaves the eunuch a soprano. From Constantinople the practice spread of using eunuchs in choirs. In the eighteenth century Handel’s operas featured castrati, who then began to dominate the opera scene, sometimes requiring composers to write in parts especially for them. Until the early nineteenth century castrati sang in the papal choir in Rome. The Italian practice of castrating boys to prepare them to become adult male sopranos did not end till the reign of Pope Leo XIII in the late nineteenth century. "

― Daniel J. Boorstin , The Discoverers: A History of Man's Search to Know His World and Himself