Zakuul was a planet located in Wild Space that served as the capital planet of the Eternal Empire.
A world with a significant southern ocean and swamps that cover the planet's surface including the Endless Swamp, a semi-solid area filled with massive, overgrown trees. The planet also had a unique connection to the Force being balanced between the light and dark sides of the Force, similar to Odessen. Zakuul was home to an immigrated Human population along with the native Iknayid but other creatures were present also and even adapted to their environment such as the swamp rancor. The planet also possessed advanced technology with several cities spread throughout the world branching off from the Spire and being the resting place of the Eternal Throne.
Zakuul was a backwater planet located within Wild Space having possessed almost no contact with the rest of the galaxy due to its position. But early in its history, the planet was conquered by the builders of Iokath meant to be one of the many worlds to be used as live testing sites for their weapons. The early Zakuulans eventually immigrated to the planet and lived there becoming a superstitious people who lived in tribes led by three Force-sensitive leaders known as Matriarch, High Shaman and Champion. In those early days, the Zakuulans believed in a deity known as Zildrog who was a mentor and guide to warriors and could gift unto them the Breath of the Dragon, a spiritual boon.
But sometimes during this age, an event occurred, the final battle between the Eternal Fleet and the Gravestone. At the end, the Eternal Fleet was shut down and the Gravestone was left in the Endless Swamp. By the height of the Old Ways, the Zakuulans had become a nihilistic people who worshiped a pantheon of gods, chief among them being Izax the god of death and Ultimate Devourer who expressed his power through the pain and suffering of his followers. They believed their fate was tied to the Old Gods and those who thought against this was branded a demon and exiled from society to the Endless Swamp alone as outcasts. But a prophecy was made that said that a Demon Savior would rise above the pantheon and slay Izax bringing about a new era; several centuries later, Vitiate appeared on the world having been tempted by rumors about the Eternal Fleet's new annihilation of Wild Space's population. He discovered Zakuul and decided to make it the home of his new empire; taking over the body of a powerful warrior named Valkorion, he claimed himself as the Demon Savior and began building from the foundations of the Endless Swamp to create his new empire.
After Valkorion's victory over the Old Ways, he united the various tribes across the world even taking their Force-sensitive leaders and re-purposing them into the Knights of Zakuul, a force sensitive order meant to protect their homeworld along with being fanatically loyal to Valkorion even creating a sub-sect of Knights known as Scions who saw visions of the past and future. The first city on Zakuul was named the Old World but it was not grand enough for Valkorion and so he continued adding onto it over and over until finally developing into the Spire. He developed their sociology and purpose for generations allowing them to become scientists and people of science rather than of brutal warriors that they had been prior to his arrival but even so, they held a connection with the Old Ways. Eventually he used the Scions to locate the dormant Eternal Fleet which was discovered using their visions and tasked the creation of the Eternal Throne, a starscraper that took an entire generation of Zakuul's best minds to build to reactive and control the ships. Once activated, many other planets were taken over by the nascent Eternal Empire expanding its influence to a sizable portion of Wild Space
Afterwards, an almost limitless amount of resources began entering into Zakuul including credits and raw materials needed to expand it further and develop its military technology which was based off the Eternal Fleet in many aspects. Each citizen of Zakuul wanted for nothing, given a monthly stipend of credits that would make them among the elite class of any core world. But during this time, the Old World turned into a place where they could live out their more darker fantasies of violence and various other suitable things that they craved before returning to the Spire. Almost for a hundred years, the Eternal Empire was at peace with the Eternal Fleet rarely being active other than a small handful of ships to collect the resources. At least until the assassination of Valkorion.
After the Battle of Zakuul, the Eternal Empire collapsed and was replaced by the Eternal Alliance, who assumed control over Zakuul. Though the planet submitted to Alliance rule, many revolts were attempted around the time of the War on Iokath. Following The Outlander's Mission to Nathema in 3628 BBY, the Zakuulans, no longer seeing the Alliance as a threat with the Eternal Fleet and Gravestone destroyed, declared their independence.