Well, I finally figured out where Karl's journal was, but I can't give it to Regis!! It finally hit me that since the Great Khans had already killed Karl, the damned game won't proceed with that quest. If it had come up to tell me that the quest was kaput (like Fallout 3 did), I could have gotten the journal first since I saved just before taunting Karl. As it is, that point in the game is long gone.
The overwhelming problem is that the game crashes so often that I save a lot now and to save disc space, I overwrite saves frequently.

No question here, just a rant.

Please join me at the Oh My Papa messed up my game party. It's getting more crowded all the time. I've just been traveling around, waiting for a patch so I can finish this game and begin another. I'm sorry it happened to you too.

There is another book that you can find which is at the fort, in Caesars tent, that tells you about Caesar turning tribes into slaves which you can give to regisas evidence.
Hope this helps?

I wondered about that. Once, when I was with a different character and further along, a Quest point showed up at Caesar's camp for the Great Khan quest. Unfortunately, by that time legion hitmen were coming after me periodocally, so it didn't do me much good.

At some point after doing enough quests for the Great Khans, when you are Idolized by them, Pappa asks you to be his heir to take over the gang after his death and you have a dialogue option to convince him to break the alliance with Caesar.