When does the stupid prologue ends? Is there a way to edit files to skip the prologue?

Nope you have to go through it to play the real game and then you can play only as the roman familys the others come later...

You can end it after Victoria told you that it is enough OR - check the senate tab - if you have conquered 5 or 7 provinces IIRC.

There is a way to play as all factions immediatly, but I really recommend playing as one of the Roman Factions first.

In the Rome Thread other posters already posted a link to such an unlock-file.

You can completely skip the prologue.

Just launch it, then ESC-it. And voilà, you can play the regular campaign.

Though, there is plenty of useful tips that are given, so I advice you to do it, or at least to turn on the advisors.

I think I had only taken two cities when I quit the prologue and started a proper campaign.

I think it was a glich that I couldn't pass it. It ended right after I conquered the first province the first time I went through the prologue. Thats why I asked.