The destruction wrought by the Great War would erase virtually all documentary evidence of the Hudrajel Empire. The details of how it functioned, and the reasons it fell are a mystery lost in the fogs of time.
What began as rioting soon devolved into civil war between the three dominant religious factions of the Empire. The newly discovered nuclear power at the time the war started was quickly weaponized, resulting in an all out nuclear exchange that was to last over a century. Population would plummet, temperatures would fall, lands become hopelessly contaminated by fallout, and extinction would become a very real possibility.
The Knetreka city of Kret carpet bombs the Tavenso occupied island of Alonis with nuclear weapons. Alonis was once the sanctuary of the Great Oracles and is the second most sacred site to the Knetreka, after Knetra'kri.
The Tavenso High Command orders the destruction of Knetra'kri in retaliation for the obliteration of Alonis. The Tavenso use six, two hundred megaton thermonuclear cobalt bombs that the Knetreka had only theorized the possibility of building in the initial attack. They then follow the attack by detonating canisters containing spent fuel rods from the Taven'kri reactor over the site to prevent anyone from ever returning.
Kret responds to the destruction of Knetra'kri by attacking Taven'kri. Though Kret's fission weapons are far less powerful, the modern, glass clad structure of Taven'kri is not designed for this kind of attack. The primitive fission reactor under the city begins to melt down when the control rods jam, and radiation levels are too high to attempt a repair.
Mon'so allies with Man'so to launch a ground invasion of Kret.
Mon'so occupies the uranium mines of Kret
The city of Kret is destroyed by Mon'so nuclear artillery. Jelakos falls back to a bunker in the Manso'tis mountains to wage a guerrilla war.
The continuing meltdown of Taven'kri's reactor has made it impossible to continue using the site. Tavenso officials destroy the site with a two hundred-fifty megaton warhead to prevent it being captured.
High Seeker Jelakos is defeated when Mon'so engineers use artillery to cause a landslide, sealing his bunker underneath thousands of tons of rubble and destroying his communications equipment. They finish the destruction with two, one hundred megaton thermonuclear warheads.
Mon'so uses nuclear weapons to destroy the Knetreka city of Julara. Saros immediately retaliates against Mon'so, and is attacked by the Tavenso city of Karos in return. The destruction of Saros damages the Utrajalek city of Arvos on the other side of the Saros Straight, causing them to attack the Tavenso city of Treska. The chain reaction triggers a global nuclear response.
The city of Kothos deploys surface to air missiles, significantly increasing their air defense and rendering them nearly invulnerable to current turboprop bombers.