Precursors

The Precursors were a highly advanced, possibly transsentient race that preceded the Forerunners, hence the name Precursor. They are believed to be somewhat overseers of the Forerunners, just as the Forerunners oversaw and protected the Human race.

It is speculated that the so-called "Mantle" was handed down from the Precursors to the Forerunners themselves. According to the idea of transsentience, it is thought that the Precursors were able to speed up evolution of intelligent creatures and travel intergalactically.

It is unknown what happened to the Precursors, although it is a possibility that some are still surviving.