From Diablo Wiki
Warriv's Journal is found on Warriv's corpse which can be found at his ransacked camp site at a random location along the Old Tristram Road in Act I. You do not need to be on any particular quest for his body to appear.
Only one of your characters needs to find the journal for you to be credited with it.
To find out which journals you have found so far go to your Achievements list (press Y) and check:
- Campaign > Act I > Historian of Tristram
|Found along the Old Tristram Road in Act I|
|Part||Text||Found on Quest|
|1||I return to Khanduras after twenty years, the burden of countless failures and tragedies heaped upon my shoulders. Am I being punished for helping that stranger hunt the Dark Wanderer? I always thought Deckard Cain half a madman, but perhaps... he was right. Perhaps he can banish the shadow hanging over my life. -- Warriv||Any|
Warriv's Journal is in some way involved in the following achievement(s).
| Books & Lore of the
|Tomes - Lore Books  In-game: People World/Quests Bestiary Diablo I & II Extra: Manuals/Other Novels History|
|Diablo I Tomes||Diablo II Tomes|
|Diablo I Manual||Diablo II Manual||D2: LoD Manual||Diablo III Manual||Other sources|
Abd al-Hazir (Writings)
|Diablo novels||The Sin War Trilogy||Diablo III novels||Diablo comics||Other books|