Until the year 15,825 BR, Ishga was a planet uninhabited by sentient life. It was in a star system as close as one could get to a black hole without being dragged into it, ensuring that it was far away from all of the galaxy's trade routes at the time. In 15,825 BR, the planet was colonized by a few refugees from the planet Arturia, fleeing from the vikings that were invading that planet.
Upon arrival, the Arturians focused mostly on village farming as they had done on their home planet, though it was less successful on Ishga since Ishga had salty, unproductive soil for the most part. A few years later, however, a cataclysm befell Atlantea, causing the entire Atlantean population (over 10,000,000 people at the time) to emigrate to Ishga. The Atlanteans and Arturians got along pretty well, with the Atlanteans showing the Arturians how to plant crops that grew well in salty soil and the Arturians showing the Atlanteans how to hunt wildlife. Soon, several farming kingdoms emerged on the planet. These kingdoms fought with each other almost constantly over farmland and other resources.
However, one of the kingdoms was called Ishga (it was called that because its first king was drunk when he named it and the name eventually stuck) and had more farmland and resources than the other kingdoms. Eventually, king Stephen I of Ishga conquered the entire planet, naming it after his kingdom. Over the next few thousand years, the Ishga population exploded since it lacked the war endemic to the rest of the galaxy. The planet soon developed into a vast ecumenopolis (planet-city), with stone towers and walls comprising the entire landscape with the exception of the north and south poles and a small strip of wilderness on the equator (all of these exceptions were designated as nature reserves to prevent the wholesale extinction of Ishga wildlife). Due to the lack of space for farming and the planet's poor soil, almost all agriculture was done hydroponically from this point on. Finding grazing space for livestock would continue to be a problem, however, forcing ranchers to encroach on the nature reserves.
Around 8,000 BR, Ishga was discovered by a Squidian trade convoy that was pulled off-course after flying too close to the nearby black hole. Luckily, the Ishgas managed to rescue the convoy before it was destroyed by the black hole, and trade relations with Planet Squid were set up. After re-learning space travel from the Squidians (the Ishgas had forgotten space travel soon after they arrived from Arturia and Atlantea), they began to search for other planets to colonize in search of terrestrial farmland. The Ishgas attempted to invade Arturia, but were easily repulsed at the Battle of Dun Leigh. When the Ishgas realized they were too weak to conquer inhabited planets, they instead turned to settling uninhabited worlds. The nearby star systems of Hosea and Carpenter were uninhabited and had rich soil, so some Ishgas settled there and set up farming colonies. Around this time, the rest of the civilized South Galaxy signed trade treaties with Ishga.
However, many trade ships were caught in the Carpenter Asteroid Belt or the black hole near Ishga's star system and destroyed. As a result, Ishga navigators were forced to plot out a safer route to Ishga from the rest of the South Galaxy. Eventually, a narrow path between the Carpenter Asteroid Belt and the nearby black hole was found. Dubbed Littleton's Pass, this passage became the only safe route between Ishga and the rest of the South Galaxy. Ishga became a trade hub, becoming extremely rich by selling its tremendous output of manufactured goods galaxy-wide. By a few hundred years before Rhys invaded Aurea, Ishga scientists had figured out how to tap into Ishga's immense coal deposits and make steam power. This triggered a planetwide industrial revolution unprecedented in the South Galaxy, with the planet's old towers and spires being replaced by steel skyscrapers.
Since inbreeding was rendering the Ishga monarchs increasingly unstable, insular, and greedy, the monarchs worked hard to restrict industry to their planet. Ishga soon had the most advanced military in the galaxy, using assault rifles and electric spaceships, while even the most advanced other planets had barely figured out muskets and were still using sea ships enchanted by Astral Magic for space travel. Various planets sought the protection of the powerful Ishga crown, leading almost the entire galaxy to have signed a military alliance with Ishga by the time Rhys invaded Aurea. The only exceptions were Caput Tatiium and some of the nascent UniSyn colonies, which would prove to be a huge problem later on.
In 2 BR, Michael (who was much more stable and less greedy than the other Ishga monarchs because his mother had him out of wedlock instead of through customary royal inbreeding) became king and changed the direction of Ishga rule forever. Since he grew up a fugitive in the Arturian wilds, he witnessed real poverty firsthand on a planet that did not have any access to Ishga technology. As a result, Michael did something revolutionary: he tested out the idea of spreading Ishga technology on the Aurean city of Olynthaseia, with the permission of Weasel (Aurea's king and a personal friend of Michael's). This initiative was highly successful, and the rest of Aurea was improved with Ishga tech over the next few years.
When Tate conquered the entire galaxy during the opening stages of his colossal war, Michael broke with traditional Ishga policy and formed the Aurean Alliance, a confederacy of planets united in rebellion against their occupiers. Once Aurea was liberated, Michael made Ishga one of the founding members of the Galactic Treaty Union, which started out as an absolute tetrarchy but morphed into a parliamentary tetrarchy as the war went on.