Great Disturbance

The Matoran Civil War occurred in Metru Nui due to a dispute between Ta-Metru and Po-Metru regarding boundaries and trade.

History
Minor disputes between the Po-Matoran and the Ta-Matoran evolved into a full scale war after the Po-Matoran sank some transport barges and the Ta-Matoran melted a Po-Metru Warehouse using Molten Protodermis. The Onu-Matoran then allied with the Ta-Matoran while the Le-Matoran allied with the Po-Matoran. The Ko-Matoran attempted to intervene, but due to being ignored, later joined the Po-Matoran. The Ga-Matoran attempted to stay neutral, but failed and allied with the Ta-Matoran.

Warfare
Arguments between Matoran escalated into combat, and the denizens of Metru Nui began fighting in the streets. Work was eventually abandoned by most Matoran, and large sections of the city were destroyed during the war. The Turaga at the time was ineffective, and could not prevent the fighting.

Makuta Mutran unleashed several destructive Rahi into the city, under the cover of the mayhem.

Archives Massacre
Miserix eventually ordered his trusted lieutenant, Teridax, to halt the fighting. Teridax took a large number of the Matoran fighters and locked them in the Archives. He then released the various exhibits on the Matoran, killing a large number of them. The battle would later be known as the Archives Massacre, and put an end to the fighting. However, it gave the Makuta a very bad reputation in Metru Nui.

Aftermath
In order to prevent similar problems, the Makuta were each assigned various regions of the Matoran universe to watch over. Teridax was assigned Metru Nui, as a prize for stopping the war. The Matoran of Metru Nui came to view the Makuta with distrust and fearful respect. The Order of Mata Nui banished the war leaders to The Pit, and placed an agent in the city to head off future problems, as there were no Toa based on Metru Nui at the time.