The government of the Betazoid homeworld, a long-standing Federation member that withdrew behind a psionic barrier after the Burn and returned in the 32nd century under President Emerin Sadal.
Betazed is a Federation member world in the 24th century, and its government is most often represented on screen by Lwaxana Troi, who serves as its ambassador in The Next Generation and Deep Space Nine. In the Deep Space Nine episode In the Pale Moonlight the planet falls to the Dominion in 2374.
Starfleet Academy reveals that Betazed left the Federation during the Burn and sealed itself behind an impenetrable psionic wall. In the episode Beta Test, President Emerin Sadal brings a delegation to negotiate with Admiral Vance, and the talks break down.
The impasse is resolved by his daughter Tarima Sadal, who proposes that the Federation build its new seat of government on Betazed as a mark of a fresh start. Sadal agrees, and Betazed formally rejoins.