Ongoing Events : The War of the Corpses(Amestris), The Amarthan Civil War(?)
Following several centuries of civil war in Amarthan territories following their near complete defeat by Xavierist Republican forces in the final war between the two states before the Republic's downfall and abandonment of the planet to form Vesperon after their own civil war ended. Several border incidents between the Republic of Fortuna and the Ulkadov State, one of the members of the Confederation of Sigma Draconis leads to a war between the two breaking out, with the Republic of Fortuna being joined by an irate Imperial Union who divert several fleets under Grand Admirals Kenshin Kurosawa and Jacob Warcliffe to attack Confederation space with the specific instructions to resolve the conflict as quickly as possible, and the Diomedian Military District's governor, Enrique de Teruel-Moctezuma, along with the Twelth Army's Marshal, Geralt von Geothe to engage the Ulkadovian and Confederate forces alongside the Fortunan Military.
The war quickly becomes a stalemate, with neither side able to make any notable gains, although multiple territories are exchanged within war zones over the course of weeks. Tired of the stalemate, Fortunan High Command authorizes Operation Doolittle, named for one of Fortuna's past Air Marshals. A nuclear strike combined with carpet bombings allow for a push across the entire front, although surviving Ulkadovian forces do retaliate with their own nuclear missiles, levelling major Fortunan cities and causing the state to go into a near collapse. The Military District of Diomedes is nuked as well, with Governor de Teruel-Moctezuma dying in the inceration of Tessare, the provinical capital. Marshal von Goethe responds with a massive strike of Amestris's infamous gas weapons, the newly created Amythest Blossom and the Crimson Blossom, either zombifying it's victims or killing them nearly instantly. Combined with the massive amounts of nuclear radiation, the zombies mutate out of control, and no longer respond to Imperial controls. They quickly begin to swell into the millions, and overrun positions of any army they reach. Civilians in the Ulkadovian state begin a mass evacuation, and then the Fortunans as the zombies begin to spread northwards. Suprisingly, some zombies show a degree of basic intelligence and pilot mechanized armor, armor, planes, or any other military vehicle in their advance foward, although not with any skill, more like if one stuck a neanderthal in these vehicles and let him pilot them.
Nuclear Radiation spreads across the planet, heralding a change of climate for the worse as humans begin to be exposed to the radiation in lethal doses, or succumb to the zombie horde spreading from the warzones or wherever the gas was carried by the wind. Evacuations begin en masse, and the war between the three powers that started all this is hastily ended with a ceasefire pre-bellum, after eight months of war. Meanwhile, back on Diomedes, 87% of the human population and likely a similar number of the alien populace have evacuated to celestial territories of their home nations, succumbed to the radiation or other toxic elements in the environment, or be reanimated as a part of the growing horde. Military forces attempt to fight back, but eventually are overwhelmed by the massive wave of flesh the mindless horde sends against them. Marshal von Geothe's 12th Army holes up in the former Amestrian capital city, and oversee the evacuation of Imperial citizens who have not already gotten off the planet, as the Grand Admirals assigned to the conflict arrive in orbit over the planet to take refugees to Archades. The 12th Army holds out for another month, but a single breach becomes a flood, and a panicked race for the shuttles begins in the military and remaining civilians. von Geothe, in his personal mech is able to engage it's VTOL engines and hover above the ruined city and escape shortly after. With nearly two thirds of Diomedes fallen to the horde, made into a nuclear wasteland, altered for the worse, or otherwise, the planet is abandoned to it's fate by most factions. Amestris occassionally sends small teams to the planet to try and harvest the unique zombie strains on it, but most of these fail.
Losses :
Diomedes becomes uninhabitale for the most part
40,000,000+ civilians
1-8,000,000 military personnel of all factions totaled
Millions of civilians displaced.