Combine-Reaper War

The Combine-Reaper War was a conflict that occured form 158 Million to 150 Million B.N.E that was mainly fought between the Empire of the Combine Race and the Reapers, the war was fought bitterly by both sides but the Reapers lost the war in the end, the resulting defeat forced the Reapers back to it's home universe and was nearly wiped out by the combines