This history takes place several millennia into the future, a future of peace where humans have extended all over the universe and learned the most profounds mysteries of the universe, including the mystery of life and the existence of God. This particularly important secret was unraveled by a genius/mad doctor that proved that, at the instant of death of a living being, a weightless particle caused and extremely small but measurable distortion in the space-time continuum by moving to a subspace that exists as a boundary between universes.
While no one ever found a way to measure any relevant data directly from that particle, as if it resisted any interaction with the world (that particle was later known to be the soul of a living being), after hundred of years of research it was found a way to create pathways using this subspace where time existed completely independent of our own universe, which immediately allowed for the instant transmission of data regardless of distance. A couple of hundred years later it was finally discovered the place where the soul was being enshrined while it's passing in the our world: the anima.
When the existent technology finally allowed to scan the subspace and observe it as a computer representation, the anima appeared as a small spherical structure with a soul in it's center. In a couple more years it was possible to interact and even create artificial anima. This was the culmination of thousands of years of dreams of immortality from the human race, because with a simple clone, an artificial anima and an automatically generated pathway in the subspace at the time of death it become possible to achieve reincarnation (and a sort of teleportation).
What followed was a chaotic, violent time where anarchy ruled. With no calms in self preservation for the current life, the worst and most destructive weapons of the human race were unleashed without calms and a new one was created: the subspace bomb. By causing destruction directly in the subspace of souls it was possible to kill a person and destroy the pathway for his reincarnation, forcing the soul to be absorbed as time immemorial in the gigantic mass of souls everyone believed to be God. Obviously the destructive power of this new weapon progressively escalated until humanity made a new discovery: a big enough explosion caused rifts in the soul subspace with a vortex in it's center. This rifts "healed" and even occurred naturally, but when two big man-made dimensional vortexes resonated with one another something appeared: a micro quasar that annihilated everything in a dozen light years while vomiting material that didn't belong to this world.
After this explosion which caused the complete destruction of the earth and the 8 nearest solar systems, which was visible from every corner of the milky way and killed directly or indirectly 40% of all humans (half of that amount could be reincarnated in a 10 year period after rebuild), a virtually unanimously consensus was reached: we must stop fighting. So a long lasting era of peace started and a couple of hundred years after the "Dimensional breach incident" our story takes place.