I'm looking for a book I read 6 or 7 years ago - maybe less.
Humanity is at war with one or more of four alien races, there is a sixth race which is a cross breed of the others. Humans come across one of the races and help them get into space or outer space. Can't remember much else apart from they find a message from their own civilizations many millennia in the past and realize that they were all transplanted to a new galaxy by their original civilizations at an almost non existent technological level due to a galactic war that devastated their original planets.