- "This is the Garden of Kadesh. For thirteen generations we have protected it from the unclean. The Turanic Raiders who came before you refused to join and were punished for this trespass. Like theirs, your ship has already defiled this holy place. If you have come to join we welcome you and will spare your ship until all have disembarked. If you have come to consume the garden you will be removed at once." — Kadeshi Ambassador
The Kadeshi were originally Hiigarans during the Exile. When the Hiigaran convoy came to the Great Nebula, at least one of the ships broke off and stayed in Nebula, thus founding the Kadeshi race. The Kadeshi developed in isolation and later began to prey on ships passing through the Nebula. The Kadeshi called the Nebula the "Garden" and it eventually became the centre of their religion. An important tenet of this religion is that any outsider ship coming into the Garden defiles it, and therefore, the intruding ship's crew has only two choices: to join the Kadeshi or be destroyed. So strong is their belief in their religion that they prefer to sacrifice themselves rather than allow anyone to leave their holy place.
The Kadeshi built large needle-shaped motherships and developed hyperspace inhibitors to capture and prevent ships from leaving the nebula. They proved to be great warriors, and eventually even the Taiidan came to fear the Great Nebula. According to the Bentusi - no one returns.
The Kushan first encountered the Kadeshi when the Kushan fleet burst into the Nebula while on their way to find their Homeworld. Unlike the Turanic Raiders and many other intruders, the Kushan fleet managed not only to repel attacking Kadeshi fighters, but also begun to strike at the Kadeshi Mothership, eventually forcing it to retreat. As the Kushan fleet moved deeper into the Nebula, the Kadeshi deployed two more Motherships for support and they trapped the Kushan Mothership in an inhibitor field while their motherships surrounded the invaders. Again, the Kadeshi offered the Kushan another chance to join them.
- "Again we offer you a chance to join us and live here in peace" — Kadeshi Ambassador
- "We cannot stay - we're on a journey. But let there be peace between us, for we have something in common. The hyperdrive technology left to us by our ancestors is identical to yours. The Homeworld we seek may be yours as well." — Fleet Command
- "You will fail. The evil that drove us here will find and destroy you. From you they will know about us and come here. This cannot come to pass." — Kadeshi Ambassador
In response, the Kadeshi sent most of their ships in massive waves and attacking from all directions with Kadeshi fighters supported by their powerful Multi-Beam Frigates. However, the Kushan fought back using their Multi-Gun Corvettes supported by Drone Frigates that proved to be a match against the fast, but lightly armored Swarmers. Eventually, the Kadeshi retreated to a wreckage of an ancient ship, possibly the very one that first brought them to the Nebula. The Kadeshi continued to fight desperately but were finally defeated by the Kushan.
With the conclusion of the battle, it is assumed that the Kadeshi were rendered extinct due to the Kushan infiltration.
- The Kadeshi are given no titles at all throughout the game and are essentially a nameless species.