In Ancient Rome castration was a well-known phenomenon. At a later period, though the Church of Rome was not well disposed towards genitalia, a practice survived until 1913 of feeling between the legs of the candidate elected pope by the conclave of cardinals before he was allowed to mount the throne of St Peter — to make sure he was really a man. Any Catholic also knows that there is a hole in the seat of the Holy Chair. After all, in the past the cardinals had slipped up. In 855 they elected a certain Johanna, and that must not be allowed to happen a second time. Once one of the cardinals had confirmed the candidate’s masculinity de visu et tacto (by sight and touch) through the hole in the chair, he pronounced the customary words ‘Testiculos habet et bene pendentes’ (He has testicles and they hang well). The cardinals then sang: ‘Habet ova noster papa!’ (Our pope has balls). Like the pope, candidate monks were closely examined for any abnormalities in those bodily parts, which they would subsequently be forbidden to use. . .
The Ancient Romans distinguished four different types: the true castrati, where both testicles and the penis had been removed, the spadones, who had lost only their testicles, the thlibiae, whose testicles had been destroyed by crushing and the thlasiae in whom only the seminal cords had been severed. Eventually castration took place on such a large scale that the emperor felt compelled to ban it. It was not doctors, but barbers or bath house attendants who carried out the procedure, and they were paid by slave traders and brothel-keepers, who initially had a monopoly. After the ban certain priests (of Cybele) continued to mutilate themselves — and not only themselves, but also any unfortunate youths who fell into their hands. They were called galli, or capons, and were destined to work as prostitutes.
In the Byzantine Empire it was also known that castrated men were less competitive and aggressive than men with testicles, which is why they were appointed as civil servants. One could take them at their word and they did what they were instructed to do, they knew they place and did not constitute a threat to the emperor and his followers.