I think I beat about 80 campaigns but the game is still not over.

Does it ever end?

I've put just under 80 hours into this game so far and am still only at 4-star Fame, with a full green bar. A lot of that time has been spent towards leveling my Books; I have about half of all the Books at 100% mastery. I've still not found the Engineering or Firearms books.

The only way to progress the story is to complete Battles (as opposed to Campaigns), which appear with an exclamation mark in front of them. When a Battle appears in your list twice, where you can choose to fight the same battle for either the English or the French, your fame level will increase when you complete the contract.

From time to time there will appear in your contract list Campaigns with exclamation marks in front of them as well. These will advance one of the many character-specific stories within the game, for example, one mission has you accompany Branwyn on a quest to assassinate a handful of Nobles, which in turn gets someone to notice how skillful she is.

Bladestorm has quite a bit of depth to it, so be prepared to drop a lot of time into it if you have any desire to reach 100% completion.

Hope that helps.