E'ronoh, the twin planet of Eiram, existed within the Eiram system as a planet. This world was characterized by its arid, rocky desert landscape. Evidence of long-gone rivers marked the surface, a testament to a wetter past. Situated in a star system that served as a hyperspace waypoint, E'ronoh frequently clashed with its twin planet over regional dominance, resulting in numerous wars throughout their shared history.
The surface of E'ronoh was dominated by mountains and rough, rocky terrain. It revolved around a star, along with its twin planet within the Eiram System. Positioned between Eiram and E'ronoh was Eirie, a moon tidally locked in its orbit. Locally, the moon was known as the Timekeeper Moon. The planet's desert environment led to frequent dust storms sweeping through its canyons and mountainous regions. Various sentient species inhabited E'ronoh, with humans being particularly prevalent. The Rook, the planet's capital city, was the seat of its monarchy. The planet was in a state of war due to continuous fighting with its neighboring planet, Eiram, by 382 BBY. The nights on E'ronoh were known for their extreme cold.
A generation prior to 382 BBY, E'ronoh became a refuge for waves of immigrants from Pantora and other systems, drawn by its reputation as a promising haven before the renewed outbreak of war between Eiram and E'ronoh.
In 382 BBY, 150 years before the cataclysmic Great Hyperspace Disaster, E'ronoh found itself embroiled in a five-year war with its twin, Eiram. A failed diplomatic mission to Eiram prolonged the conflict. Niko A'lbaran, the heir of Monarch A'lbaran, was dispatched for peace negotiations. However, the mission ended tragically when the transport experienced an accident, causing Niko's demise. In response, Monarch A'lbaran intensified attacks on Eiram, prolonging the war.
During the war's fifth year, a humanitarian corridor was established to facilitate the delivery of water supplies to the parched population of E'ronoh by an ice hauler. This brief respite was shattered when a fighter from Thylefire Squadron entered the corridor and initiated an attack on the Eiram fleet, which was perceived as an act of aggression, prompting a retaliatory response.
As hostilities erupted, Longbeam cruisers of the Jedi arrived, providing assistance requested by Eiram. These Longbeams proceeded to Eirie to assess the damage caused by the crossfire. Supreme Chancellor Orlen Mollo joined the Jedi group, which included Jedi Master Creighton Sun, Jedi Knight Gella Nattai, Jedi Master Char-Ryl-Roy, and Padawan Enya Keen. The Jedi intervened swiftly to de-escalate the situation, with Knight Gella Nattai successfully gathering information from Princess Xiri A'lbaran, the Captain of Thylefire Squadron.
The ship that violated the corridor had been seized without the pilot's consent, Bly Tevin. Captain A'lbaran and Jedi Knight Nattai attempted to regain control of the ship, but their efforts failed. Consequently, A'lbaran deliberately crashed the ship, carrying both herself and Tevin, into the Eiram ocean near Erasmus Capital City, averting a direct impact on the city. Tevin perished in the crash, while A'lbaran swam to the coast of Erasmus, where she encountered Phan-tu Zenn.
The princess of E'ronoh was transported to Erasmus Capital City and met with Queen Adrialla. Following discussions with Zenn and the queen, the Jedi persuaded Monarch A'lbaran to engage in peaceful negotiations aboard Chancellor Mollo's Longbeam. As the peace talks commenced, both leaders exhibited hesitation, causing concern for Master Sun. Viceroy Ferrel of E'ronoh fueled the discord between the two. Princess A'lbaran and Prince Zenn proposed an intermarriage between the two worlds, uniting a daughter of E'ronoh with a son of Eiram, to resolve the conflict and establish lasting peace.
With a fragile peace taking shape, Jedi Knight Nattai accompanied the heirs and Axel Greylark, the son of Co-Chancellor Kyong Greylark, as they delivered humanitarian aid to the suffering populace of E'ronoh. During their journey through the deserts, they faced various dangers and challenges. As they returned to The Rook, Zenn and A'lbaran grew closer. As the wedding of the heirs approached, Greylark and Zenn investigated a research facility containing a particularly potent type of poison gas. Following the discovery of the poison, Zenn confronted his mother and learned the truth about the deal that was made and broken between Eiram and the Path of the Open Hand. On the wedding day, Axel Greylark devised a plot to eliminate the Republic and the Eiram system's leaders. Viceroy Ferrel's son planned revenge on the heirs for the princess's "weakness" against Eiram. Both plans were thwarted as Nattai managed to reactivate the city shields in time, and Princess A'lbaran killed the Viceroy's son.
Following Axel's imprisonment by Republic forces, Jedi Knight Nattai suggested that the heirs hold the signing of the peace treaty on Jedha. Both heirs agreed, and long-awaited peace seemed imminent.
E'ronoh dispatched Ambassador Tintak to meet with his Eiram counterpart in the Second Spire of Jedha City. The signing was overseen by Jedi Master Sun, Mediator Morton San Tekka, and the Guardians of the Whills. As the signing commenced, a rogue security droid bypassed security measures and detonated. The explosion resulted in the death of San Tekka, leading to Tilson Graf taking his place. During the second attempt to sign the treaty the following day, rioters, incited by the Herald of the Path of the Open Hand, attempted to breach the spire. While evacuating to his shuttle, Ambassador Tintak was assassinated by a speeder carrying an individual dressed in an Eiram military uniform. E'ronoh's forces accused Eiram of the attack and assaulted Ambassador Cerox's bodyguards. E'ronoh forces were deployed and engaged Eiram's in the city. The Jedi stationed on Jedha managed gain control of the conflict, and both armies retreated to their homeworlds. With the treaty signing all but lost, peace with Eiram was uncertain.
During a period of cold war between the two worlds, E'ronoh was governed by Monarch Cassel, a Pantoran. Cassel was abducted by members of the Directorate, who also kidnapped Queen Thandeka of Eiram, initiating a hostage crisis that prompted both worlds to seek assistance from the Jedi Order. As the Eiram–E'ronoh crisis unfolded, Eiram and E'ronoh jointly offered a ransom to the Directorate and launched their own investigations into the kidnappings. Following the resolution of the crisis, relations between Eiram and E'ronoh improved significantly, and they grew more receptive to the Republic, permitting the construction of the Starlight Beacon within their territory.
During the Galactic Empire's reign, E'ronoh was under Imperial control. At least one Star Destroyer orbited the planet, and stormtroopers patrolled its cities. Smuggler Sana Starros and the Weequay criminal Jand raided an Imperial warehouse, discovering several Po'acksters. However, Starros chose to leave without taking them, stating that she did not deal with livestock.