Summary Of The Fireteam Pegasus Story
The Covenant War
During the war many on both sides were killed in a number of decisive conflicts were it not for many brave acts Humanity wouldn't exist today but some deeds remain more important than others.
Battle For Ulqrell
Although not much of the battle has been shown small bits of lore have been revealed that indicate that the planet Ulqrell once held Forerunner structures similar to the like of both Song and Lyric, due to the conflicts it is theorised that by the present Ulqrell 's monitor had to make the world go dormant in modern times to stop outside interference.
When James Chain started the EARTHBOUNDS he set in course a series of events that forced the galaxy into chaos. As the EARTHBOUNDS gained traction many other smaller rebellion groups were formed and the UNSC was forced to create numerous top secret project in hopes of eliminating the threats once and for all.