

They enthralled the lesser species in the galaxy and protected them in exchange for their servitude, but these lesser races created intelligent machines to serve them. An ancient race referred to as " Leviathans" - supposedly a species that had reached the apex of its evolution - had all but dominated the Milky Way galaxy many eons ago. The details behind the birth of the Reapers were brought to light in the Mass Effect 3 expansion pack "Leviathan". This cycle of death was ended at the end of the third game in the series, almost always costing the player character's life.

These massive constructs exist so that any intelligent life in the galaxy would eventually discover them and base their technology upon them – all part of a scheme to harvest the galaxy’s sentient life in a repeating cycle of purges that has continued relentlessly over countless millennia. The Reapers were the original creators of the Citadel space station and the mass relay network. Even their true name is a mystery "Reapers" was a name bestowed by the Protheans, and Sovereign stated that whatever the Protheans chose to call them was of little concern to its kind.

The first Reaper known to have communicated with organic life, referred to as Sovereign, claimed that the Reapers have neither beginning nor end. They hibernate there, dormant for fifty thousand years at a time, before they are given the signal to return. The Reapers reside in dark space, the vast, mostly starless space between galaxies. The Reapers are a highly advanced machine race of synthetic-organic starships from the Mass Effect video game series.
