A remote, subterranean planet, Utapau was located deep in the Utapau system of the Tarabba sector in the Outer Rim Territories. Largely isolated from the wider galaxy, the planet was an ancient and windswept celestial body that was dotted by deep sinkholes, with societal organizations co-existing with its abundant animal and plant life, in a state reversed of that to other planets. Spanned by a world-reaching subterranean ocean, which created the countless hundreds-of-meters deep sinkholes that formed across the surface, the planet was around 57,000 BBY by a species that genetically evolved into the Pau'an and Utai species, with the former creating civilizations across the grassy plains while the latter ventured and dwelled in the sinkholes. Sometime later, following the colonization, the surface world had become plagued by massive hyperwind storms as Utapau's environment shifted significantly, forcing the Pau'an civilizations to seek refuge alongside their fellow natives, where the two developed a symbiotic relationship and established several city-states, such as the capital of Pau City.
Although loosely governed by the politically dominant Utapaun Committee, rivaling city-states often engaged in regular battles and conflicts, in disagreements regarding resources and political gains. Eventually, however, the Utapaun Committee was able to unite Utapau, representing numerous city-states and overseeing planetary and interplanetary affairs. At some point, later on, Utapau became the adopted homeworld of both the Amani, from the planet Maridun, and the Sugi species. The technologically disadvantaged and isolationist tribes of Amani established villages and small communities in the bottom of sinkholes and across the wind-ravaged plains on the surface.
A peaceful world, Utapau sought to remain neutral and unaffiliated during the three-year, galaxy-spanning conflict of the Clone Wars. However, it was invaded by the droid armies of the Confederacy of Independent Systems late into the war and placed under heavy occupation as it acted as a temporary hideout for the Executive Separatist Council and General Grievous. When the Galactic Republic's own forces arrived in pursuit of the droid leader, Utapau's military gladly joined forces with the clone troopers in combating the droid army to liberate their homeworld, only to be placed under a new occupation as the Republic transitioned into the Galactic Empire.
An Outer Rim world located deep in the Utapau system, Utapau had a temperate climate and a rocky terrain of desert plains and large sinkholes. The planet had a population of 95 million. Pau'ans and Utai were native to Utapau, while the Amani had settled on the planet by the Clone Wars. The majority of Utapau's Amani lived deep underground. Bands of Sugi also lived on the planet.
Below Utapau's surface was the massive "world-ocean," a huge subterranean body of water. This water contained many powerful currents created by the tidal forces of Utapau's moons. These currents eroded the underside of the planet's crust and caused the formation of Utapau's many sinkholes and chasms, which, when combined with numerous storms, served to make the planet's surface inhospitable. One of Utapau's "continents" was more stable than the rest; for that reason, most Utapauns lived on that stabilized continent.
Because of the lack of timber on the planet, Utapaun architecture was primarily constructed out of the bones of deceased animals. The bones of nearly all of the planet's fauna were used in construction, which later developed into a unique form of architecture known as ossic architecture. The skeletons of the huge animals that roamed the lower sinkholes and ocean had huge enough bones to be used as beams; other fossil bones were mined in caves.
At least 57,000 years before the Battle of Yavin, Utapau was colonized by a race of humanoids, who eventually evolved into two sentient species.
Hundreds of years before the Clone Wars, the native Pau'ans lived on Utapau's surface while the Utai colonists lived underground. Eventually, worsening hyperwind storms and extreme weather forced the Pau'ans to move underground with the Utai, building combined cities into the ledges of giant sinkholes. Stripped of trees by the violent winds of the surface, the new cities were built with numerous animal bones, eventually resembling giant animal skeletons to the casual observer. Additionally, the planet's formerly extensive oceans had long been draining underground, forming the sub-crustal world-ocean. The Utapauns' fresh water was extracted from machines that purified the seawater and also separated any valuable minerals from the ocean. Eventually, it was determined that the world-ocean contained a number of valuable substances that the planet began to export.
During the High Republic Era, the Utai Raik lived in the lower levels of the Republic capital planet Coruscant, with rumors arising that she had been exiled from Utapau and her home clan due to her love of taking vicious trophies of victims. In 232 BBY, Supreme Chancellor Lina Soh temporarily prohibited hyperspace travel in the Outer Rim Territories after a catastrophe known as the Great Hyperspace Disaster. The Disaster saw the freighter Legacy Run fall apart whilst travelling through hyperspace, causing it's fragments to emerge from hyperspace across the Outer Rim at random. The hyperspace ban meant that many Outer Rim worlds suffered food shortages as usual shipments were halted. Despite receiving special aid shipments, Utapau suffered food riots in its sinkhole cities.
Obi-Wan Kenobi and Boga fall into the sinkhole after being fired on by the clone troopers.
During the Clone Wars, the Confederacy of Independent Systems sought the planet. Despite this, the planet remained neutral. Late in the war, Anakin Skywalker and Obi-Wan Kenobi were sent to investigate the death of Jedi Master Tu-Anh. This led them to locate a massive kyber crystal that the Confederacy was attempting to acquire. They were able to destroy the crystal before it could fall into Separatist hands.
Within months, the Separatists invaded Utapau with thousands of battle droids. Later, a number of key Separatist leaders were stationed on the planet, but were moved to a mining complex on Mustafar prior to the battle on the orders of Darth Sidious. General Grievous remained on Utapau to oversee the battle, but met his end at the hands of Jedi Master Kenobi. Unfortunately for him, Supreme Chancellor Palpatine issued Order 66 shortly thereafter. Because of their behavioral modification biochips, Kenobi's clone troopers turned on their Jedi General and shot him down into a sinkhole. However, Kenobi survived and escaped Utapau. After the end of the Clone Wars, the Galactic Empire occupied the planet, leading to a number of Pau'an refugees leaving Utapau. The planet gained representation in the newly formed Imperial Senate, which in the opinion of its senator Daho Sejan allowed its people to prosper and thrive instead of being extinguished, but Utapau's people nevertheless greatly resented being under Imperial occupation and spat upon the Senator's very name, viewing him as having sold them out to gain comfort and wealth for himself.
By around 17 BBY, the Pau'an medical students Fyzen Gor and Greesto Ftrak were abducted by the Wandering Star criminal organization. One of the gangsters shot Ftrak in the chest, and he fell into a coma. Gor later killed Ftrak by removing one of his arms, and attached it to a medical droid. Over the next two years, Gor built a small army of droids augmented with organic body parts, which drew Wandering Star's attention once more. Most of the droids were destroyed in a brief skirmish, and Gor was forced into the service of the gang.
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