The Ekosians are a humanoid species native to Ekos.
In the mid-23rd century, their world was in total anarchy. Federation historian John Gill soon violated the Prime Directive by establishing a modified Nazi government on their planet, believing that the Nazi government was only violent because of Adolf Hitler. However, Gills subordinate Melakon soon became power hungry and seized control of the planet.
Soon, the Ekosian government began to use the people of the neighboring planet Zeon as scapegoats for the planets troubles, similar to Adolf Hitler's attitude towards Jewish in Europe.
The USS Enterprise arrived to discover the fate of Gill just as the "Final Decision" was to be put into effect. The crew found Gill and were able to revive him in time to stop Melakon and his plans.
By 2268, relations with Zeon still remained strained and eventually exploded into full scale war. The Federation did its best to broker peace between the two planet, but the war continued.