Some say it was the will of the gods, others say it was just a disease. Whatever it was killed the civilization of the Quiet Forest.
If it was a plague, it was oddly virulent and strangely selective. It seemed to only target intellegent creatures, and among them the survival rate was perhaps something less than one in a thousand. The neighboring lands were oddly unaffected, although they did quickly ban all travel from the Quiet Forest. Banned is perhaps too mild a term, as to this day anyone leaving the area is killed on sight. Admitting that you come from the Quiet Forest is generally a self administered death sentence.
Oddly though, people coming into the Quiet Lands do not get the plague until one of the plague cycles happens. This occurs on a poorly understood cycle. About every five years or so those from the outside experience the die-off, but if you've survived a cycle, you will not sicken, even in the midst of the plague. Children born of survivors are not immune to the cycles, so parenthood is heartbreak for those who dare the will of the gods and have children. Children are cherished, but the population has been shrinking for a long time, and everyone expects that someday there will be nothing but the wild. There are various mythic fortellings of a breaking of the cycles, but the general feeling is one of hopeless fatalism.
No one alive remembers a time without cycles. These cycles have been going on for a long time. No one is sure how long, but the walls around the region are both massive and old. Interestingly, the walls have no gates, so they obviously were built in response to the plague. The only permeable borders are the sea to the north, and the Hard Lands to the south. The lands of Bliss, Kazak, Pernod, Farn and the Plains all have well funded borderers to keep the infection contained.
The land is a place of large trees, abundant game, and very few people. Those people who live in the land have preserved as much as they could, but there are large ruins where a once proud civiliation had flourished. The forest has reclaimed the land, and the few cities and villiages live mostly from small farms and hunting. Much of the ancient lore has been preserved, but there is effectively no communication with the outside world.
The players are orphans raised in an institution funded by the surviving population. Their parents came over the wall about twenty years ago, and all died in one of the plague cycles. Outsiders do come in, lured by the tales of riches and the prospect of free land. Their surviving children, when there are any are brought to the institution and raised. The institution is the primary school, and repository of ancient knowledge. There are typically about a hundred or so children and young adults living there. The infant mortality rate in the quiet forest is such that very few children survive to their tenth birthday.
The institute also collects ancient artifacts, books and coin, it requires that each child raised serve for at least three years after they achive majority.
You as players have just acheived your majority and are now beginning your service period.