Hi,

I'm writing a fictional story, of which I have pretty much the entire story in terms of the events that take place, but I'm really struggling with the setting. It is a historical setting, but not being an expert in history, I'm struggling with an exact location and time period to set the story in. If I may outline the requirements I need from the setting in order for the story to work, and if anyone can help point me to a location and time period in history that best suits these requirements I would really appreciate it!

the story centres around street gangs, so I need a city big enough for street gangs to operate, thieving, racketeering etc, and for these gangs to be able to operate and essentially control goings on in large parts of the city.

I'd like these gangs to have knives or swords as their weapons, so basically it needs to be a time before guns were used or at least used by gangs in this context.

the story involves prostitutes and so this must be legal and commonplace.

also involved in the story is a rival gang that have tracked someone they are after who has money that he stole from them, from another city/area to the main city that the story takes place in.

This rival gang need to be a scary proposition to the central gangs.

I've thought about london, but I dont know which time period is best for essentially one main street gang to be able to control a large area of such a big city, and I'm unsure of where the rival gang can originate from that they would travel to london and be a scary proposition to the gangs of london.

Again, if anyone can help with suggestions, I would really appreciate it.

Thank you!