Prior to 1484
The Turei Alliance is a space-faring military and economic confederacy of species native to the Gradin Belt. Founded in 1484 when the Turei united with their neighbors to defeat the Vaadwaur, the Alliance has existed for nearly a millennia through a mutual interest in control over the Vaadwaur Underspace. In 2388, Task Force 38 signed a non-aggression pact with the Turei Alliance.
For hundreds of years, the Vaadwaur maintained a tight grip on the Gradin Belt through control of the Underspace, a set of subspace corridors throughout and beyond the Gradin Belt that provided a major tactical advantage over other regional powers. When the Turei became warp capable in 1300, the Vaadwaur immediately tried to subjugate them. The Turei resisted, and the Vaadwaur responded by leveling several Turei colonies. Rather than break their resistance though, this only strengthened the resolve of the Turei. Over the next hundred and fifty years, the Turei sought out neighbors who, under the banner of the Turei Alliance, eventually pushed the Vaadwaur back. In 1484, the Alliance's campaign culminated in an orbital bombardment of the Vaadwaur homeworld, retribution deemed fitting for the crimes the Vaadwaur had committed against their people.
With the Vaadwaur no more, the Turei Alliance transitioned from a joint military operation to an economic and defense partnership focused on maintaining control of the Underspace it had taken from the Vaadwaur. While each species in the Turei Alliance retains sovereignty over their planets and colonies, administration over their economic zone, military forces and territorial claims as a whole is handled by the Turei Alliance's Navy, Parliament and Prime Minister.
Nearly a thousand years since the defeat of the Vaadwaur, the Turei alliance is currently a full-fledged interstellar power with a burgeoning economy, an impressive fleet of ships, hundreds of cubic light years of territory and alliances across the Gradin Belt. They are wary of intrusions into their territory and challenge any ship found or attempting to use the Underspace, but otherwise maintain fairly peaceful relations with their neighbors.
In 2376, the USS Voyager discovered a Vaadwaur battalion that had survived in stasis pods on their homeworld. While the Turei destroyed a large number of the surviving vessels, fifty three managed to flee into the Underspace. Since then, the Turei have renewed their mandate to exterminate the Vaadwaur, expanding their patrols and sending out expeditions through the Underspace to search for any signs of the return of the Vaadwaur.
Even though some Turei hold the Federation responsible for reviving the Vaadwaur, their fear of the Vaadwaur led the Alliance to propose a mutual aggression pact with Task Force 38 against the Vaadwaur. While Task Force 38 was unwilling to enter into such a pact, they did sign a non-aggression treaty in order to protect their tenuous holdings in the Gradin Belt. This treaty allows the Federation to use the Underspace so long as they are escorted by a Turei ship. The Alliance entered into this compromise so as to avoid having to vie with yet another power for control of the Underspace while they try to hunt down the remaining Vaadwaur survivors currently working to reassert control of the Underspace.