Insurrectionist (Earth-5875)

Insurrectionists, also known as insurgents, rebels, and Innies, are various different groups of human revolutionaries and separatists devoted from the eradication of the Unified Earth Government and the United Nations Space Command, including their influence and government of the Outer Colonies, becoming the main enemies of the interstellar empire during the Secession through varied factions. With the rise of the First Contact War, most Insurrectionists chose to ally with the UNSC out of necessity, although some conflicts still occurred in the war.

Secession
Vast majority of the Insurrectionist movements commenced in the Outer Colonies, in 2494 with the rise of the Sovereign Colonies movement, a leadership so organized it was able to create its own military. The Sovereign Colonies demanded their independence from the Unified Earth Government, directly opposing the United Nations Space Command. As many of the Outer Colonists believed the UEG to be an oppressive regime that did not care about them, coped with the payment of taxes to the Inner Colonies, made the movement, and many other copy-cats such as the United Liberation Front, incredibly popular during their prime. For the next two decades the fighting spread through human territory.

In 2511, the Freedom and Liberation Party, a rebel movement based in the Eridanus system, was able to overthrown the Republic of Eridanus and control majority of Eridanus II's cities. The UNSC response was the search of violently putting the rebellion down. Mamore, a planet whose history is filled with war and violence, was the source of major riots in 2512. Two days after the start of the riots, an Insurrectionist detonated a nuclear device in the Haven arcology, which killed two million people and injured 8.3 million.

The pivotal Operation TREBUCHET occurred in mid 2513, which became one of the largest military operations ever launched by the UNSC in its history. The main objective of the operation was to fully eliminate the massive presence of the Sovereign Colonies in the Inner Colonies once and for all. The decisive victory over the Sovereign Colonies at Tau Volantis during TREBUCHET saw the end of both the movement and the Sovereign Colonies Armed Forces, with the UNSC achieving a pyrrhic victory at the loss of four destroyers. Despite the fact the Sovereign Colonies were all but finished, with many of the corporates interested in the movement signing for peace, multiple sympathizers escaped into the Eridanus asteroid belt and created their own covert military bases.

In 2525, the Office of Naval Intelligence discovered that several Insurrectionists loyal to rebel commander Colonel Robert Watts had infiltrated the UNSC Fleet Command and revealing key military information. In the same year, SPARTAN-II Blue Team infiltrated Watts' base at Eridanus Secundus, killed all of his soldiers, and took him into custody.