The Sky Fortress was Seratos's most famous creation.
Humans had been using balloon airships for over a thousand years. They were one of thousands of practical technologies developed by the ancient Utoran Duchy.
But after the Holy See's trial of White Niven over eight hundred years ago, religion's oppression of the Academic World caused countless practical technologies to be gradually lost as the age that birthed them faded into obscurity.
Seratos, who had studied under Fladick, the War King, was obsessed with planning, designing, and researching massive war machines.
Unlike Fladick, who was devoted to humanoid mechanical devices, Seratos pursued the construction of a more comprehensive, greater, and more powerful platform for war.
With his genius, he spent years after graduation traveling between the Utoran Duchy and the ancient ruins of Starveil Land, even making three trips to the Central Orora Empire. After a century of effort, he finally designed the blueprint for the Sky Fortress war platform!
No one knew where the inspiration for his brilliant design had come from.
It was a glorious age for the Academic World!
The Crusade Army's expedition to Night's Veil Land had ended in defeat, loosening the constraints on the duchies. The dark history of religious oppression was about to give way to a second dawn. The Academic World of the six great duchies gave rise to renowned Royal Academicians, who stood at the forefront of the search for truth and knowledge. They broke through the darkness of ignorance, expanding the branches of the tree of knowledge in fields such as natural law and evolution's profound meaning, and lighting beacons of wisdom.
It was in this same era that the political systems of the Grand Duchy and the Xilan Duchy underwent radically different changes.
The Xilan Duchy was the first to overthrow its