This war began around 500 years ago, during the Archaic Era, following the normalization of genetically-altered humans/designer babies who became superior in virtually every way to the natural born man. As these designer humans aged and grew in population, they became the idealized humans and were some of the most powerful, influential, wealthy people of the time. Using their status and affluence, they began to demonize and outright attack the common people, referring to them as animals and considering them unevolved. Eventually, the Normals had enough. Riots began worldwide, and before long, a world war began, not between governments of different nations, but between the Ascendants and the Normals, both using the weapons and support of their governments, depending on whichever group their governments allied themselves with. The Ascendants and their military in western nation created the CURSE, which they were immune to but that wiped out a great deal of Normals. After the discovery of aether and the introduction of it to humans however, the tides turned, and Normals were able to fight back. Unfortunately, it was too late, as most of humanity had already been wiped out by biological warfare. With so many less people, societies crumbled, infrastructure went into disrepair, and without civilization, trade, agriculture, etc. virtually life as it was ended. Anything that was not necessary for day-to-day living disappeared. It was considered a post apocalyptic age, when civilization needed to be rebuilt. Much was lost over the years, including a vast majority of technology. As the generations continued, survival was all that mattered. This became known as the Calamitous Era. Even during this dark time, the CURSE managed to exist and threatened life again and again, causing more untold amounts of death. Eventually, precautions were taken, tricks were learned to avoid the bat-like robots harboring the deadly virus, and information was passed between villages and towns to better prepare for any attacks. After centuries, humanity began to grow and prosper once more, and a new steam-powered era began, paired with a type of rudimentary clockwork technology. This new, current time, starting around 250 years ago, became known as the Resurgent Era.
These decade-long battles took place roughly 100 years ago in the country of Lluminox. These battles were raged primarily between Ascendants with the Lluminotic Imperium (who felt their noble place in society was threatened) and Aethaumaturges (with Normals mainly on the sidelines). It concluded with Ascendants and King Mordus being victorious and Aethaumaturgy prohibited in the country of Lluminox, with the punishment being life imprisonment. Shortly after the Aether Crusades, King Mordus was beheaded by his enemies (some believe were followers of Artimus Thorn, who had since disappeared).