From Diablo Wiki
The Manual header is transcribed here. All the manuals of the Diablo games contain a lot of lore of the world of Sanctuary, and is one of our primary sources of information. They contain texts that are meant to be excerpts from books and tomes written in the actual in-world existence of characters, but as a reader you need to be aware of the fact that much of the actual years written down have been "retconed", and is no longer canon. This means that we currently don't know exactly what yearly calendar is actually canon information. However, the actual events that take place are usually somewhat correct, so if you are adding material from the manuals to an article, feel free to add years and events into the article, and we will have to update the article when more accurate information comes out from Blizzard.
Some words have been wiki-linked for easy information navigation, and in some cases the formatting has been changed to work with the wiki. No words below the introduction (this text) has been altered.
Make sure to read all of the manuals:
- Diablo I Manual
- Diablo I: Hellfire Manual
- Diablo II Manual
- Diablo II: Lord of Destruction Manual
- Diablo III Manual