The idea of the assassin often invokes the image of the lone gunman, working on his own to eliminate whoever he views as a threat. But a handful of groups have recruited enough of these individuals to assemble into entire organizations—made up of those willing to kill for what they believe in.
10. The Vishkanyas
The vishkanya, deadly and beautiful assassins, were developed in ancient India to end conflict between kings without widespread violence. According to the ancient literature, one way of grooming a girl was to dose her with poison a bit at a time, until she built up an immunity to it. She would then be sent into an enemy camp or tasked with getting close to a rival king, administering poison to him while being able to eat and drink from the same vessels to allay suspicion. In other cases, the girl might be purposely infected with a poison (spread through blood or sexual contact) or an infectious disease, before being dispatched to the rival capital or camp.