Following the Great Deluge, those Atlanteans who survived were sequestered inside the domed city of Poseidonis. The Atlantean mystic, Shalako felt that the technocratic Atlanteans were "unclean", so his followers and he mounted an exodus through the tunnels beneath the city and re-established themselves in Tritonis. Shalako used the dark magics at his command to create a hard-water dome around the city that protected the Shalakites from being crushed by the ocean depths. Shalako's brother, Orin, had developed a means to transform the Atlanteans into an amphibious race, and offered this technology to the Shalakites. Shalako refused Orin's offer, but his followers readily accepted the ability to leave the confines of their city at their choosing. Shalako took this as an insult and the ultimate betrayal. He cursed the people of Tritonis, transforming them into a scaly race of fish-people. Those affected by Shalako's curse eventually evolved into the modern day Mermen and Mermaids.

One of the most pivotal events to affect these early Tritonians was the birth of Kordax. Kordax was the result of a violent rape between the Tritonian Dardanus and the Princess of Poseidonis, Cora. By right of birth, he was therefore heir to the throne of Atlantis. The Poseidonians refused to acknowledge Kordax's alleged birthright, and it wasn't long before war erupted between the two city-states.

In the modern era, the most notable Tritonian was King Iqula and his wife S'Ona. The Tritonians were always an isolationist culture, and they shied away from the other major Atlantean population centers. When the capital city of Poseidonis began rising to the surface, many displaced Poseidonians were forced to seek refuge in King Iqula's domain. The Tritonians greatly disliked this, and the overwhelming influx of Poseidonians caused great conflict between the two races. Iqula pressed the displaced Poseidonians into indentured service, where they remained for several months until the day that the super-hero Tempest convinced Iqula to set them free.