Combine

The Combine, abbreviated as CMB, and referred to in propaganda as "Our Benefactors" and a "Universal Union" by Wallace Breen, is an immense inter-dimensional empire, comprised of a number of species either as allies or as slaves. The Combine's ultimate goal is to enslave and control the Multiverse.

Following the Black Mesa Incident, and the death of the Nihilanth, the Combine invaded Earth and emerged victorious from the ensuing war against the humans in a mere seven hours with their extremely superior technology and the assistance of numerous enslaved species, completely taking over all of human civilization and ruling with an iron fist, oppressing and murdering humans while destroying the planet slowly via drainage of resource. Nevertheless, humanity did not remain subjugated, and nearly twenty years later, Earth's Resistance culminated in The Uprising, and the Combine werebeaten thrice in pivotal battles.

These events were spearheaded by Gordon Freeman, having been released by The G-Man from stasis. The Combine serves as the overarching antagonistic force of the overall Half-life series and is the main antagonistic force of Half-Life 2, its episodes, and Half-Life: Alyx.