The governing council of the peaceful Halkans, led by Tharn, which refused the Federation the right to mine dilithium for fear the crystals might one day be used to take life.
The Halkan Council governs a people whose ethics forbid any part in violence. It appears in the Original Series episode Mirror, Mirror, in which Captain Kirk tries to negotiate mining rights to the planet's rich dilithium deposits.
The council's leader Tharn accepts that the Federation is benevolent at present but will not risk the future. Kirk assures him that Starfleet will not take the crystals by force.
An ion storm then throws Kirk's landing party into a parallel universe, where the Terran Empire's Enterprise has orders to destroy the Halkans if they refuse, and where the council's counterparts are equally ready to die for their principles. Kirk stalls the attack and urges the mirror Spock to change the Empire. Back home, the council's decision is left to stand.