What's the history of your fictional world, especially the parts that lead to the current setting of your story?

I'm a worldbuilder and writer, and I wanted to hear about other peoples' fictional worlds, especially the history leading up to the current point. I'm happy to share a bit about my world as well. I think it's interesting comparing the little differences in how people tackle world building so please share as much as you'd like about your world and its history.<br><br>**My World:** This one is set in a post-apocalyptic future (a common theme I'd imagine) about 100 years after a solar flare eradicated most of the world. The story will take place in North America, specifically in the south west.<br><br>The world was similar to ours up until a series of fault lines ruptured beneath the ocean and triggered massive earthquakes and tsunamis along the coastal areas. The global effects were immediate and a large portion of the world's population was wiped out. Society collapsed as governments and economies were strained to their limits and eventually fell apart.<br><br>A few large countries attempted to work together to try and reunify the world under a common banner, but they were quickly faced with a short series of brutal wars that decimated the world once again. After years of bloodshed, the world was returned to a "dark ages" state. Small tribal villages, city states, and fiefdoms arose in the absence of the former governments. These petty squabbles often lead to small, brutal wars over resources.<br><br>Enter into the scene large industrial corporations who had weathered the world's collapse by utilizing their large networks of resources and production. They slowly began buying up large swaths of land, developing and protecting it, and the governments of the 21st century looked away as they continued to grow in size. As governments subsided, these corporations became the new governments, and old nations began to fade away as more and more people were assimilated into corporate nations. This is the state of my world, and where the story will begin.