I am currently in the process of creating my own world, in a Victorian Era/Industrial Revolution/Steam Age setting. It's not overly steampunk but light elements of it are acceptable, as well as some dark fantasy/horror here and there (inspiration from H.P. Lovecraft's works, without going full Cthulhu).
Anyways. I've always loved the idea of mafias and how they function, operate and exist fascinates me.
My question is the following :
What are some good resources (books, websites, videos, documentaries etc..) out there that explain how a mafia sets its roots, how it becomes an important and recognised entity and how they maintain that power?
I am looking for resources specifically, not direct answers to my questions (although ideas and inspiration are always welcome)
Some extra questions that may help understand what I am looking for :
What are the essential elements to take into account when creating a believable mafia that has an impact in a city or region?
Could they control for example all grain sources, aka food? How would they go about that and how would they exploit it?
Could there be multiple families squabbling at the top over who controls what?
How does a mafia get rooted into a city so deeply that even the authorities don't dare approach them?
What makes a mafia powerful?
How does a mafia begin?
How can I make the mafia impactful and interesting enough that my players will recognise them without just kicking down the door and plowing through to the "big boss"?
What am I missing?
Any and all ideas are welcome, I'd love to read/watch more on the subject.