United Liberation Front

The United Liberation Front (ULF) was an alliance of various human insurrectionist and separatist groups that arose in the 2510s following the dissolution of the Secessionist Union, which had up until then been the most notable union of insurrectionists on an interstellar scale. While the ULF remained prominent throughout the 2510s and 2520s, the Human-Covenant War and the destruction of most Outer Colonies, along with the capture, surrender or death of most of the movement's leaders, saw the effective breakdown of the ULF by the 2530s. By 2535, little of the ULF remained, with most of its former adherents either having joined the war effort, gone to hiding, or dead.

While the ULF was always a loose association of groups at best, it distinguished itself by its strong and well-coordinated core group, which was able to strike against the UNSC in multiple systems across large swathes of the Human Sphere. This has been attributed to the ULF's strong leadership, which was near-universally comprised of high-ranking UNSC defectors. Outside the core group, there existed many peripheral insurrectionist groups which pledged allegiance to the ULF's cause but had little coordination with its leadership, often due to astrographical realities.