The forerunner

The Forerunner is the translated name for the ancient race of enlightened beings that were the creators and builders of the Halos, the Ark, the Shield Worlds, Onyx, along with the artifacts that were found on the planets Reach, Earth, Sigma Octanus IV, Harvest, and Arcadia. All that is known about the Forerunner has been gleaned from these various artifacts. The predecessors of the Forerunner are thought to be another alien race, known as the Precursors. The alien faction known as the Covenant worshiped the Forerunners as gods, deriving much of their technology from Forerunner artifacts found throughout the galaxy, and believing any who tampered or destroyed these relics to be heretics.I have got this info from halopedia.com