Like a grim eagle upon it's nest, the great black block of Tannia Castle looks down upon the city of the same name. Despite the fact that some of those brought within it's walls never come out again, the castle is still looked upon well by most of the city's inhabitants, a place of protection rather then a place of terror.
"Binding the Life Coil" is an ancient quasi-mystical technique rediscovered to prolong one's life at the expense of one reproductive ability. It is a simple magikal technique that anyone can learn (a skill or feat). The promise of near immortality or a lifespan of a thousand years or more makes everyone want to learn it.
This technique has a price though, the amount of immortality is in direct response to the strength of ones reproductive spirit. Those that have never breed will live longer than those that have. The use of the technique makes conception difficult, if not impossible. So you trade the future of your society for the chance for you to see much of that future.