The Great Conflict is the term for the eternal war between Heaven and Hell preceding the creation of Sanctuary. The Diablo II game manual offered a lot of lore not found in-game or in novels. For that matter, we have made updates to DiabloWiki to make this lore available and at your reach.
DiabloWiki is growing by the day, and remember that you can make a difference even with a small thing such as a few data updates on a page, or adding a link here or there to serve the community in general. Your help will allow fans to look up characters, locations, spells, items, runes and more with the advent of Diablo III.
Feel free to read the Great Conflict and other stories from the game manual.