|Grand Alliance|| Clergy of Mardük|
| Cardia †|
Kagetsu II †
| Distreyd Thanadar XII †|
The Great War was a world-wide war that took place between the Yamatian Invasion and the Cataclysm in the years 1003-1006 AE. It was fought between the armies of Light led by King Marcus Sarillius of Remon and King Kagetsu II of Maar Sul who wished to liberate oppressed kingdoms and the armies of Darkness led by High Cleric Distreyd Thanadar XII of the Clergy of Mardük and Shogun Masamori Hyuga of the Yamato Empire who wished to keep the whole world in their grip. The war ended in a draw, and the following Cataclysm changed the world permanently.
- Main article: Yamatian Invasion
Shogun Masamori Hyuga of Yamato and High Cleric Distreyd Thanadar XII of the Clergy of Mardük combined forces and united Yamato under one banner. Before the neighbouring nations knew what was going on, Distreyd used his magic to envelop the whole world in nightmares while the Shogun's armies conquered the kingdoms one after another. By 1003 AE, practically the whole world, except a few pockets of resistance in Aison, was under the Yamatian yoke.
In 1003 AE, three years after the Yamatian Invasion, Leon Alcibiates led a rag-tag group of people into Tes Pellaria. There he met the Faerfolc and invoked the spirit of Agarwaen who had once been the king of Manster which had become Remon. Agarwaen told Leon that a certain paladin from the group, named Marcus Sarillius, had the blood of kings in his veins and thus would be his rightful heir and the next king of Remon.
The heroes who had accompanied Marcus and Leon became collectively known as the Fellowship of Tes Pellaria, and they began drafting people from villages in Northern Remon and eventually even formed an alliance with dwarves of Drithenspire.
After many battles against the Yamatians and agents of Mardük, the fellowship reached Folsworth Woods. They eventually managed to form an alliance with the elves there after doing a few quests. A Maar Sulais delegation led by Kagetsu II appeared too, pledging Maar Sul to Marcus's cause in return for Marcus's help in the liberation of Maar Sul from Yamatian tyranny. The fellowship and its new allies came to be collectively known as the Grand Alliance, and Marcus and Kagetsu II became the leaders of the Alliance's growing army.
The Grand Alliance succeeded in liberating Remon after many battles, and it did the same to Maar Sul and Aison. Libaterra was almost saved, but the Faerfolc Rampage and the accidental Reactor Core Explosion caused so much damage that the Alliance had to flee from Libaterra and head for Yamato. The heroes scored many decisive victories and even managed to raid Vulpengaard Keep, the base of the Clergy of Mardük, during which Distreyd Thanadar XII and Kagetsu II were killed.
The heroes eventually pushed the Yamatians and agents of Mardük back and had the final battle of the war near Kageshima, the Yamatian capital. Mardük appeared during the battle and opened the portal to the Demon Realm. The Godslayer arrived soon after and devoured Cardia and Mardük, starting the Cataclysm.
- Main article: Cataclysm
After the deaths of Cardia and Mardük, the demons ran amok and slaughtered everyone that stood in their way. The Alliance was forced to flee back to their countries of origin, and the Great War came to an end albeit with a terrible cost as many people died in the rampage of the Godslayer and the demons. The Age of Emptiness had begun.