Ender In Exile: Ender Series, book 6 (Ender Saga)

At first, Ender believed that they would bring him back to Earth as soon as things quieted down. But things were quiet now, had been quiet for a year, and it was plain to him now that they would not bring him back at all, that he was much more useful as a name and a story than he would ever be as an inconveniently flesh-and-blood person. At the close of ENDER'S GAME, Andrew Wiggin - called Ender by everyone - knows that he cannot live on Earth. He has become far more than just a boy who won a game: he is the Saviour of Earth, a hero, a military genius whose allegiance is sought by every nation of the newly shattered Earth Hegemony. He is offered the choice of living under the Hegemon's control, a pawn in his brother Peter's political games. Or he can join the colony ships and go out to settle one of the new worlds won in the war. The story of those years on the colony worlds has never been told... until now.