Forerunner

The Forerunner race were a highly-advanced and ancient Tier 1 species whose empire, the Ecumene, encompassed three million fertile worlds in the Milky Way galaxy approximately 100,000 years ago, but, much like that of Humanity, the Forerunner's true history has been dated to be around 35 Centrillion years ago. The Forerunners were the creators and builders of many significant installations, including the Halo Array, the Ark, and the Shield Worlds, as well as numerous lesser artifacts later found on many worlds. The Forerunners are independent, though a sizable population is found in the Second Human Empire