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 xenophobic and isolationist.
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 associate membership in the United Federation of Planets in 2370, the Prytt suspected it to be a plot for a military alliance between the two. They abducted Starfleet officers Captain Jean-Luc Picard and Dr. Beverly Crusher for interrogation, though Kes operatives were able to effect their escape. Kes and Prytt representatives met aboard the USS Enterprise-D to discuss the fate of the two prisoners. The situation deteriorated rapidly, with both sides leveling wild conspiracy theories and childish arguments against the other. Eventually, Commander Riker lost patience with the negotiations and threatened the Prytt with massively increased Federation scrutiny unless their officers were returned. (TNG: "Attached")