Creation Story(Short Version): the world was a dark place filled with dragons and evil shit. Then the First Flame showed up, he created and gave a part of it to 4 people. They became known as gods because the with the flame they created the world. Eventually some asshole dragon/Dark Lord guy, came and created the abyss(Pure Evil!!!!), the world of light fought back, they created the Abyss Watchers and used countless men to fight back. Sadly they lost. All the 4 "gods" became corrupted. In a last attempt the last people locked away any undead(they rose from the dead because of the abyss) in a undead asylum. That is where dark souls 1 begins. This was a short,mostly accurate version. And believe or not there is lore just like this in every game.