2142 CE

In 2142 CE, the Unggoy were discovered on their homeworld of Balaho by the Covenant and forcibly added to their list of member species.

2462 CE

Following years of abuse of Unggoy at the hands of the Kig-Yar culminating in the sterilization of thousands via poisoning, the Unggoy Rebellion began in 2462 to protest their treatment by the Kig-Yar and the Covenant as a whole.

2492 CE

In 2492, soon after the end of a devastating civil war between Jiralhanae that caused a total collapse in Jiralhanae society, the Covenant visited the Brute homeworld of Doisac and invited them to join.

The Battle of Sigma Octanus IV was a large-scale space and ground battle between UNSC and Covenant forces in the Sigma Octanus system in July 2552.