The Prytt Alliance was a government that controlled one-quarter of the planet Kesprytt III in the 24th century. The Prytt were members of the Kesprytt species like the citizens of Kes, the nation-state controlling the other three-quarters of the planet. Unlike the Kes, the Prytt were reclusive and xenophobic.
The Prytt were led by a prime minister, whose office was held by Horath in 2370. There was also a security council, led by the security minister; in 2370, Lorin held the post. As there was no formal contact between the two governments, there were no ambassadors and no emergency contact procedures involving the Kes.
When the Kes applied for membership in the United Federation of Planets in 2370, the Prytt viewed it threateningly. The Prytt were so suspicious of the Kes that they kidnapped Starfleet officers Captain Jean-Luc Picard and Dr. Beverly Crusher when they beamed down to the planet. Kes and Prytt dignitaries met aboard the USS Enterprise-D to discuss the fate of the two prisoners. The situation deteroriated rapidly, with both sides leveling wild conspiracy theories and childish arguments against the other. Eventually, Commander Riker lost interest in the negotiations, refused Federation membership to the Kes, and demanded the return of his people. (TNG: "Attached")