The World Building Community put out a prompt 2 days ago, asking us to describe a fallen civilization in our setting, and go into a bit of detail about what they were like, and who they were.
Here's A Link To The Prompt Post If You'd Like To Get Involved.
The Beskin Home World
Besk is a place I actually haven't spent a whole lot of time, but I do like the general idea I have for the place, and some ideas I have floating around for their world, culture, and what happened to them prior to joining the rest of Free Space.
The Beskin's are a humanoid race, completely covered in fur and on average they're pretty small - measuring at around 5,7" - of course, there are exceptions to their average height. They have a strong sense of smell, and use it as a way of remembering vivid details about their past - for example - there is one of the characters in the stories, Flux, who works as a hired gun for a gang on Jex, and he carries an old rag that he occasionally sniffs to remember a friend of his who the piece of clothing belonged to, and he uses it as a way to comfort himself and think about her.
Most Beskin's are very isolated from each other, and only feel comfortable forming close friendships with non-Beskins, due to a rare mental disorder they can develop known as "Degradation" which has affected their people since the dawn of time.
Degradation
Throughout time they have suffered this disease and have never found a way to cure it. When a group of Beskin's become close, they create a hierarchy among themselves, and before they've realised it, the group descends into a sort of hive mind, where the chosen leader has total control over all other members, and typically, they become ravenous monsters who attack and kill anyone who isn't a part of their Den.
The only way to break the spell is to kill the leader, but to save all of the other members this must happen quickly because, after an extended period of time, the minds of those affected are too far gone to be saved, leaving the only option, execution.
There are entire industries on their world that revolve around destroying Dens and taking out anyone affected while trying to save anyone who can be. The only issue with saving people is, that it's very dangerous, so most people opt to just take the easy road and wipe them all out. The other reason for people to choose this option is because even if someone is saved early and broken from their Den, the damage to their mind leaves them in a constant state of confusion and they can sometimes hallucinate and have delusions.
When multiple different groups come into conflict with one another, a leader is established, and the fallen leader's group will merge with the rest, swelling the numbers of the Den, and making them a much larger threat to society.
The Falls
As far as historians can tell, the Beskin civilization fell more than five times, leaving their people in a terrible position where their advancements were concerned.
Beskin society has been in a constant battle with these forces, and their population fluctuates drastically, especially around the time of a fall. Breeding programs, as a result, are a time-honored tradition on Besk, one to ensure a diverse gene pool, and also to ensure that their population stays above a certain threshold.
Most Beskin's leave, at least for a little while, but every male is told to give sperm donations prior to leaving, just in case they were to never return.
Recordings of each fall and the wars to reclaim their world from the hordes of mindless monsters are considered some of the more terrifying of Free Space literature and have led to a brand of fiction that is sought after. Beskin authors are considered the best when writing about social issues, like mental health, and loneliness, and sometimes their work is known to inspire people from all walks of life. On the flip side, Beskin's are considered introverted, rude, and shy, but this is only because their society demands isolation from an early age, to try and keep Dens from forming.
Rebels tend to break these rules and traditions, and those are the ones who typically cause outbreaks on their world, and at that, are considered - by their society - some of the worst people in the world.
While there aren't a lot of records of their prior worlds and cultures, there have been studies made that state that all Beskin's of today are the evolution of a complete hive mind takeover, which is a scary prospect for any of them to imagine. As it would mean that the ones today have far less mental capacity as the ones before the falls.