Revolution
The Insurrection era includes events spanning from 2494 FS to 2525 FS. The era includes UTF operations against the Rebel/Insurrection forces in the Outer Colonies, the continuation of the ORION Project and the creation of the SPARTAN Program.
The Insurrection is the proper name given to an undeclared civil war fought between the United Terran Federation and various loosely organized groups of rebels, collectively known as the Insurrectionists, over control of the Outer Colonies, which began in the year 2494. Originally, the breakaway movements started as disquiet against the Ministry of Colonization's oversight of the Outer Colonies, with the colonists tired of the organization's often overbearing bureaucracy. It first started as peaceful protests, and after years of frustrating negotiations, some groups began to use more forceful methods, eventually abandoning diplomacy in favor of terrorist tactics. Initially confined to a few systems, the fighting spread across human-controlled space in only several years; as the conflict escalated further, even some Inner Colonies, as inwards as the Epsilon Eridani system and even the Sol system itself, were targeted by rebel militants and terrorists. What had once been widespread support for the Insurrectionists quickly dried up at the outbreak of violence. Though they started out targeting only military and Ministry of Colonization targets, as the UTF counterinsurgency operations began, more and more innocent people were caught in the crossfire. The Insurrection claimed millions of lives between the late 2490s and the mid-2520s. The various rebel groups had become extremely adept at creating improvised explosive devices difficult for the UTF to detect, and therefore stop, and had struck many high-profile targets, even in orbit above Reach itself. Some opponents of the war believed the simplest solution was to simply give the rebels their autonomy - for the UTF to pull out, and let the rebels have their independence. However, the value of the colonies made them simply too important to abandon, as it would bankrupt the Inner Colonies. The Insurrection quickly died down after the onset of the Human-Covenant War that began in 2525. Many Insurrectionists prioritized fighting against the Covenant due to them being a common enemy as well as the outer colonies being the Covenant's first targets. With aid from the UTF, the rebels reached a compromise with the UTF and the civil war was brought to an end.