The Grunt Rebellion

The Unggoy Rebellion was a large-scale revolt by the Unggoy against the Covenant Empire in 2462.

History
It was started by the Infusion Incident when the growing Unggoy population put pressure on the Kig-Yar, with whom they shared their habitats.

The overwhelming Unggoy population forced many of the Kig-Yar to relocate, killing many of their eggs and forcing the Kig-Yar birth rate to decline.

In an effort to exact revenge, some of the Kig-Yar poisoned the Unggoy infusion resources, recreational narcotics used in the Unggoy's portable methane supplies. This made the contaminated males sterile, escalating the conflict between the two species. After the Prophets failed to respond to this, due to the Ministry of Concert rejecting a junior staffer's request to investigate the matter further, it escalated into a short but aggressive conflict, forcing the High Council to instate an Arbiter. The conflict ended only when the Unggoy homeworld, Balaho, was almost completely glassed by a Covenant Fleet.

The war showed that, when motivated, the Unggoy could be vicious, determined and competent fighters. Following their warrior tradition, the Sangheili who had defeated the uprising forgave the surviving Unggoy fighters, trained them, gave them better equipment, and allowed them access to weapons, which the Unggoy had previously been forbidden to have.

The Sangheili also integrated the Unggoy into formerly Sangheili-only units, elevating them from unarmed cannon fodder to true infantry forces. However, the war kept the Unggoy in a lowly position within the Covenant

Timeline
This event began the 39th Age of Conflict, and after the Unggoy were forced back into the Covenant, ushered in the 23rd Age of Doubt.