Explanation: When the famously corrupt and arbitrary Roman Emperor Nero discovered one of the Imperial slaves looked like his recently deceased wife (whom he himself had killed, according to some accounts), he had said slave, Sporus, castrated and had a marriage ceremony in which Sporus was subjected to the position of Nero's bride.
Nero was not exactly a model of human behavior by any society's standards. Later Roman Emperors would outlaw castration entirely.