"This is your first and only warning, your last chance for salvation. We come to you not as missionaries of any false gods, nor as liberators from them. We come to wipe your pathetic kind, like the scourge you are, from the face of the galaxy, to kill and slaughter until none remain. We are the Der'kal, and this is the beginning of your end..."
—Der'kal commander; at first contact between his people and the Alliance.
The Der'kal Invasion, also referred to as the Der'kal War, was the single-deadliest conflict in the history of the Milky Way Galaxy, rivaled perhaps only by the thousands of years of on-and-off infighting amongst the Goa'uldSystem Lords. Waged between the reborn Alliance of Great Races and the Der'kal Empire, the conflict eventually resulted in the extinction or near-extinction of several species, widespread planetary destruction, severe civilian and military casualties on both sides, and the displacement of hundreds of millions of refugees.