Darkseid was the ruler of the nightmare world Apokolips and ruled over other worlds that he has conquered. As a New God he was a conceptual being existing outside of the normal universe in a realm called the fourth world. He was called the god of evil and, while there were few in the multiverse that could surpass him in his monstrousness, Darkseid was more accurately the god of tyranny. As such he would not stop until he conquered all of creation and the entire multiverse. To this end he sought out the Anti-Life Equation, a power that would allow him to turn anyone or anything into his mindless thrall completely bound to his will.
Darkseid's plots against Earth were many, and they led him into frequent conflict with its heroes, incuding Superman, Wonder Woman, Batman and the Justice League.
Note: In Post-Crisis New Earth continuity, Darkseid destroyed during the Final Crisis event.
