Leron was a revolutionary who lived in the realm known as Dimension Aqua. Years ago, his followers and he led a revolt against their world's reigning queen, Mera. Forced into exile, Mera escaped to the Earth realm where she befriended the Atlantean hero, Aquaman. Leron pursued her and came to blow with Aquaman and his friends Aqualad and Qwsp. Leron apprehended the heroes and brought them all back to Dimension Aqua as prisoners. Aquaman discovered that the lead found in oil could negate Leron's hard-water powers, and he used this tactic to free Mera and the others. Mera returned with Aquaman back to Atlantis, enabling Leron to solidify his position as the new lord of Dimension Aqua.
Years later, Mera returned to Dimension Aqua in search of a healing device, which she needed to save the life of her son, Arthur Curry, Jr. She discovered that Leron had confiscated all of the tools from her reign and cast them into the Great Pit. Leron and Mera faced each other in one-on-one hard-water combat. Though Leron was potent, his powers were no match for Mera's who easily overwhelmed him. The battle proved to be such a strain for Leron that his mind was shattered, turning him into a vegetable.