When the Survivors first resurfaced in 2140, they were met with immediate hostility from the surface mutants. In fact the first survivor that peeked his head out of the vault had his head blown clean off. The Survivor army engaged in a series of skirmishes against the Evolved warbands and attempted to recolonize the wastelands, in what was later to be known as the Great Surface War of 2140. Thanks to the brilliant tactics of one young field commander, the Survivor army was able to make decisive blows against Evolved encampments.
But despite the commander's efforts and the Survivors' technologically superiority, they were forced to retreat back underground after seeing how bad the war was going; little progress was made in reclaiming the surface as the seemingly endless hordes of the Evolved keep striking back.
After spending another 40 years underground, the Survivors prepared once more to reclaim the surface. Not only did the Survivor army had to deal with an even more mutated Evolved, but their exploits in the previous war has angered the Series 9; in the fighting of the Great Surface War, the Series 9's crops were destroyed.