WARNING: The following article contains spoilers for director James Wan's Aquaman, in theaters now.
When Jason Momoa as Aquaman in February 2015 with an image bearing the phrase "Unite the Seven," it kicked off more than two years of speculation about what that might mean for Justice League. Although some fans held out hope it was indication that DC's Green Lantern might join the six established heroes, as the ensemble film approached, it became clear the slogan had nothing to do with Justice League, and everything to do with Aquaman.
It's, of course, a reference to seven kingdoms of Atlantis, the sunken metropolis and the six realms that splintered from it after the Great Fall thousands of years ago. It's a concept introduced by writer Geoff Johns during his run on DC's Aquaman comics, a major influence on the film, where those kingdoms were referred to as the Seven Seas. Atlantis and Xebel, long part of the comic book mythos, were joined there by the Trench. But the remaining realms make their debuts in director James Wan's film.
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Aquaman also takes us back to the cataclysm that sank ancient Atlantis, a kind of sci-fi Rome not too far removed from Asgard of the Marvel Cinematic Universe. It wasn't a natural catastrophe or even the wrath of the gods, but instead hubris, resulting in the descendants of the ancient civilization living as seven separate kingdoms, scattered beneath the waves.
Atlantis
Introduced in 2017's Justice League, Atlantis is built upon the sunken ruins of the ancient kingdom. Although the shimmering capital is, on one hand, married to some puzzling architectural traditions, such as the centuries-old bridge that leads to a great gateway in a massive city wall, on the other, it's a technological marvel illuminated by towering Portuguese men-of-war. The incongruities don't end there, however, as Atlanteans speed through the water in futuristic vessels and ride in vertical, subway-like trains, while soldiers ride astride armored sharks.
It's ruled by King Orm (Patrick Wilson), Arthur Curry's younger half-brother, who seeks to wage war on the surface world in revenge for centuries of pollution dumped into the seas, and to secure his claim to the throne of Atlantis. If that means killing Arthur, whom he blames for their mother's death, then so be it.
Xebel
Ruled by King Nereus (Dolph Lundgren), Xebel in the DC Extended Universe is an untrusting ally of Atlantis that intends to mend the strained relationship with a political marriage between Princess Mera (Amber Heard) and King Orm. Suspicious of Orm's ambitions, Nereus nevertheless joins with Atlantis when he's led to believe the surface world is plotting an attack.
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In DC comics, Xebel was originally an other-dimensional kingdom ruled by Mera, before it was reimagined as a penal colony for Atlantean criminals only accessible through the Bermuda Triangle.
Fishermen Kingdom
After the ancient kingdom sank beneath the waves, the Atlanteans and Xebellians quickly adapted to life underwater but retained their human appearances. By contrast, the Fisherman Kingdom evolved to closely resemble the creatures of the sea, complete with gills, scales and fish-like tails. It's somewhat reminiscent of the Atlantean city state of Tritonis from the comics, whose dominant race are mer-people.
More concerned with poetry and philosophy than the politics of Atlantis, the Fisherman Kingdom is nevertheless drawn into King Orm's plans to unite the undersea kingdoms against the surface world.
The Brine
Aquaman doesn't provide any formal introduction to the Brine, but they play a central role in the film's climactic battle, as King Orm and his Xebellian and Fishermen allies attack in an effort to force the kingdom to join in a war against the surface. Like the Fishermen, the Brine evolved beyond a human appearance. They're a crustacean-like race, possessing an armored shell and crab claws.
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Described as "a violent but intelligent race" in The Art and Making of Aquaman, arriving Jan. 1 from Insight Editions, the Brine are fierce warriors who "understand strength over reason," particularly when it comes to the defense of the borders of their kingdom.
Deserters Kingdom
The first kingdom to separate from Atlantis, the Deserters retreated from the Atlantic Ocean to an inland sea where the Sahara Desert now stands. Once Atlantis' grand armory, where Atlan's trident was forged, the kingdom went extinct when the waters disappeared.
Arthur and Mera seek the buried ruins of the Deserters Kingdom, now buried by sand, in a sequence that combines elements from such 1980s action-adventure touchstones as The Jewel of the Nile and Raiders of the Lost Ark. It's there they discover the next clue to the final resting place of the sacred trident.
The Trench
Although they were originally like any other Atlanteans, after the Great Fall the people who would become known as the Trench migrated to the deepest, and darkest, places in the ocean, the Mariana Trench. Adapting to their harsh surroundings over thousands of years, they didn't so much evolve as devolve, coming to resemble the sea life that thrives in such an unforgiving environment.
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Resembling vaguely humanoid anglerfish or dragonfish, with massive, razor-like teeth and claws, the light-averse Trench are predators that swarm anything that enters their territory. Introduced in 2011, in DC's Aquaman #1, the Trench of the comics are among the three known surviving sea kingdoms, and follow the wielder of the Dead Men's Scepter.
The Lost Kingdom
The final kingdom is a bit of mystery, so we're left to piece together what few clues there are. The so-called Lost Kingdom is included in a list of the seven, and then never mentioned again in Aquaman. Presumably, like the extinct Deserters, the Lost Kingdom can neither help nor hinder Orm's plan to be named the Ocean Master and lead a war on the surface, so it's of little consequence.
But it's possible -- maybe even likely -- that the Lost Kingdom is actually where Arthur and Mera discover Atlan's tomb, the Hidden Sea at the Earth's core. Accessed by a rift in the kingdom of the Trench, this Hidden Sea is a prehistoric place populated by dinosaurs. But the Dead King's Island, as it's called in The Art and Making of Aquaman, is horseshoe-shaped, like ancient Atlantis, and Atlan's tomb isn't a mere cave to which the legendary king retreated; parts of it, at least, are carved by the hand of man, or, rather, Atlantean.
Directed by James Wan, Aquaman stars Jason Momoa as Aquaman, Amber Heard as Mera, Patrick Wilson as Orm, Willem Dafoe as Nuidis Vulko, Yahya Abdul-Mateen II as Black Manta, Temuera Morrison as Thomas Curry, Dolph Lundgren as Nereus and Nicole Kidman as Queen Atlanna.