Earth, 2673

After 160 years as refugees, humanity has returned to Earth.

Evicted from its birthplace, the forces of the United Colonies of Mankind have spent almost two centuries mustering their armies to launch a mass war against their enemy: the dreaded Scourge. Alien parasites from an unknown galaxy, the Scourge appeared without warning, destroying the previously peaceful society. What they didn't kill they captured and enslaved, forcibly bonding with their hosts.

Fighting off the parasitic threat as well as enemies from the enigmatic alien Shaltari and the splintered Post-Human Republic turned humanity into a militant race, one with a manifest destiny amid the stars.

The UCM launched their Reconquest campaign to take back the Cradle Worlds – verdant paradises seized by the Scourge. The battles have been long and fiercely fought, ending in costly victories that left the colonial fighters exhausted. Humanity is nothing if not tenacious though.

After a brief hole opened in the Scourge's defences by the courageous Resistance fighters left planetside, the UCM have seized their opportunity to attack. Their forces are battered, but the surprising opportunity of an assault on Earth itself is one that couldn't be passed up.

The power of the space-based fleet and the mobile troops of the UCM's army is mighty, but still not enough to fight even the weakened Scourge armada. At the eleventh hour, aid has appeared from some unlikely sources, forming one of the largest fleets ever witnessed.

The board is set; the Battle for Earth has begun.