Numero Uno was a ringed planet located in Galaxy Zelta. It was home to a humanoid species, embroiled in war.
The native humanoid population had been driven from the surface of the planet as a result of toxicity from the rings. As a result, they were forced to end their war which had lasted for centuries. When the USS Enterprise explored the planet, the inhabitants (who had relocated to two satellites orbiting the planet) tricked the Enterprise crew into removing the rings. However, the Enterprise crew then forced them to end their war. (TOS comic: "The Ghost Planet")