Eswen, officially known as the Republic of Eswen, was an island nation situated in Sera's equatorial region. Due to its location, with half of the nation on the equator, the island had varying climates and biomes, resulting in a jungle environment in the north and a more temperate southern region. During the Pendulum Wars, Eswen fought as part of the Union of Independent Republics where there impressive Navy defeated Coalition forces in several important battles. In 27 B.E., the COG launched a large-scale invasion of Eswen, utilizing Army, Navy, and Marine forces, fighting their way to the capital and forcing an Esweni surrender. The COG annexed the nation soon after, using it as a staging ground to launch further assaults in the region.
After the Pendulum Wars, the Esweni began a massive rebuilding project to rebuild their Navy and was well underway when the Locust emerged six weeks after the Armistice. This slowed down, but not halted, the construction of numerous ships, which would become invaluable when the island had to be evacuated. For eight years, Eswen contributed troops and supplies to assist Coalition forces on the main continents, unfortunately, in 8 A.E., the Locust finally emerged on the island and within weeks had reduced the population from twenty four million to thirteen million. Over the next several months, the population continued to drop until the decision was made to abandon the island to the Horde. The remaining five hundred thousand people made their way to ports all over the country, evacuating onto the many naval ships, unfortunately, many people had to be left behind, causing over four hundred thousand people to be abandoned.
After the evacuation, the large fleet of ships, easily over a thousand and composed of both military and civilian vessels, sailed together; however, by the Battle of Ephyra in 10 A.E., the fleet had split in half. By the time of the Lightmass Bombing, only small flotillas remained, and when Jacinto was sunk in early 15 A.E., ships operated by themselves. During this time, it was unknown how many people remained alive on the island, as no ship dared to return for fear of the Locust many thought would be waiting for them. Unbeknownst to them, several thousand people survived in the forests and jungles of the island, careful not to draw attention to themselves.
Unfortunately, in early 16 A.E., the Lambent began emerging on the island, seemingly sensing out the surviving population, bringing the Esweni people even closer to extinction. As the pandemic spread over the island, it forced both human and Locust populations out of their respective areas and into closer proximity with one another as it destroyed settlements and poisoned farm land. Fighting an increasingly close quarters two-way battle with both the Locust and Lambent drained what little resources the Esweni had left, but with nowhere left to go, they fortified their last settlements as best they could and decided to fight to the last. In 17 A.E., the entire Locust population of the island launched an all-out assault on the remaining humans, seeking to take their fortifications to protect themselves from the Lambent, who joined the battle soon after. Perhaps only hours away from complete destruction, the surviving Esweni were saved by the timely activation of the Imulsion Countermeasure Weapon on Azura, seemingly killing off both the Locust and Lambent.
Soon after, a massive flotilla of ships, lead by the CNV Bastion, arrived at the island carrying thousands of Esweni and tons of supplies, including new technology recovered from the computer banks of Azura. After rebuilding enough settlements to house the returning refugees, the new government went about disposing of the Locust shells, dumping them in the remains of the Locusts' settlements and several mines that had been abandoned during the war. Over the next two and a half decades, Eswen slowly rebuilt itself, mostly staying on the coast as the land became more fertile as the Lambent toxins were diluted and dissipated. In 40 A.E., the government began sending settlers to try and recolonize the interior of the island, an endeavor that was successful until 42 A.E., when several settlements and their militia garrisons went missing. The Esweni High Command dispatched several companies of soldiers to investigate, but what they found was worse than they could have ever imagined. The settlers and soldiers had been taken by a monstrous new lifeform known as the Swarm, thus bringing a new war to the island and its people.