Ages of Discovery (Earth-2042)

The Ages of Discovery were periods of time where the Covenant developed leaping technolical achievements. The San'Shyuum, with the help of the huragok, developed numerous advanced technologies, reverse-engineered from forerunner artifacts.

The Twentieth Age of Discovery occurred in the late 600 BBY. It was during this period that the Ardent Prayer was constructed. The Shadow of Intent was built during the Third Age of Discovery, circa 587 BBY.

Source

 * https://www.halopedia.org/Ages_of_Discovery