The Underworld was first an organised creation of people who wished to operate without the prying eyes of their respective nation's laws and government. With this sole goal for freedom to do whatever they wanted in a world without rules, hundreds of people across the globe came together to create the Underworld.
Drugs, murder, kidnapping, slavery, all crimes that would've been punishable under regulated laws, were acceptable in the Underworld, even expected - newcomers were often warned about this particular fact.
However, upon the arrival of the First Great War, which plunged the entire world into chaos, what was once a paradise for criminals came to an end.
With the world in an uproar over the destruction and death, people began to migrate into the Underworld, for in their eyes, it was much safer than being on the surface.
