I was roaming around Halo wikia, and when I got to John-117 page i was reading his battles. And in the list it mentioned he was in the Insurrection which was a civil war that took place before the Human-covenant war. Here's the Page:
http://halo.wikia.co...ki/Insurrection
What I was thinking, What if they were to a prequel to the first halo trilogy about this war. Master Chief will still be in it and all. I think it will be really cool if they were to do it, the story seems really interesting and it will work great for a game. Pretty much the only difference i can think of is that you will be fighting humans, the rebels, instead of aliens.