The Ventaxians were a humanoid race native to the planet Ventax II. In their mythology, their version of the Devil was known as Ardra. Over a thousand years ago, Ardra saved the Ventaxians from crippling civil war and famine, and promised them a millennia of prosperity in exchange for their enslavement afterwards.
When, in 2367, she returned to receive her planet and people, they were ready to submit, and would have, had not the crew of the USS Enterprise-D been there to uncover that she was in fact an impostor. (TNG: "Devil's Due")