What body does Gemini rule?

Could you please explain to me which celestial body or entity is associated with the astrological sign Gemini and is considered to be its ruler? I'm curious to know if it's a planet, an asteroid, or perhaps a different type of cosmic body that holds sway over those born under the sign of the Twins. Additionally, I'd like to understand if there are any specific qualities or attributes attributed to this ruler that are believed to influence or characterize Gemini individuals.