The First Demacian-Noxian War was a historical period in which 
Noxus conquest was halted by 
Demacia, resulting in Noxus' dominance declining for half a century. Meanwhile 
Piltover started making scientific advancements with the discovery of Brackern crystals.
History
- 787 AN - 892 AN
In an effort to find suitable fuel sources for hextech, the 
Ferros Clan, led by Elicia Ferros, went on an expedition to 
Shurima. There they found the slumbering Brackern and attacked them, ripping their lifestones out of the creatures' bodies. 
Skarner awoke and lashed out, killing several people. Elicia is injured and the Clan is forced to retreat. Several weeks later Skarner began his quest to recover the stolen lifestones, and succeeded in retrieving one. Many were brought to Piltover and used to fuel hextech, becoming known as the first "Hex Crystals". The ultimate fate of these crystals remains unknown.
This attack on the Brackern seemingly led others to also hunt the Brackern, but to what extent remains unknown. In the modern era, rings made from "sing-stone" are traded by the Shurimans of Kalamanda and Urzeris. After decades of shadow investments in chemtech and runic alchemy, the Ferros family brought to market less powerful, but easier to procure, synthetic hex-crystals. The production of synthetic crystals is rumored to be a heavy contributor to the Zaun Gray.
During the last few centuries, Noxus had set out which it had sworn to achieve. The Noxian warbands had annexed most of Central Valoran under their banner. With confidence, they marched onward, aiming for the western shores of Valoran.
- 892 AN - 895 AN
The Noxians, who had been met with little resistance finally met their match, the Kingdom of Demacia. The battle-hardened Demacians had specialized themselves defending against any onslaught. Outmatched, the Noxian warbands were driven eastward by Demacia's armies, harrying them back behind the walls of Hvardis, a fortified settlement south-east of the Gates of Mourning. After hearing of these setbacks, 
Sion, who had been campaigning in the Argent Mountains, now turned his warband towards Hvardis in order to reclaim the lands that he and his warband conquered.
When Sion's warband arrived at the front, they were met by the Demacian armies on the horizon. They had no intention of pursuing the Noxian warbands any further, seeing as they had driven the invading army from the lands neighboring their own, they were preparing to return home. The commander at Hvardis had decided to let the Demacians leave without inciting any further assault. Outraged at this display, Sion hurled the commander from the city walls, and ordered the attack.
With only his warband following his charge, Sion flew into battle with the Demacian forces but was quickly outnumbered. Alone, pierced by a dozen of the enemies' weapons, he finally reached the enemy commander, King Jarvan I. Sion grasped the king by his throat, attempting the strangle him. Only when the enemy commander stopped breathing, did Sion allow himself to die. With their king slain, the Demacians made a retreat back beyond their borders. As Noxus mourned Sion passing, his corpse was entombed within a towering monument constructed to honor him for all time.
- 895 AN - 942 AN
Over the next half a century, Demacia would end up freeing the countries of Central Valoran from Noxian dominance, pushing the Noxians back towards their capital.
- 942 AN - 945 AN
Stevan Ferros personally oversaw the induction of Hakim Naderi as the lead artificer for the Ferros family, a promising young crystallographer from the Shuriman coastal city of Bel'zhun. 
Camille with the help of Hakim augments her body, installing a Hextech Heart that slowed down her aging while changing her personality to be more cold and calculating. As a result of this change in personality, Camille and Hakim part ways.
Sion's tomb was reopened. The ruling Grand General of the empire, Boram Darkwill, was willing to pay almost any price to restore Noxus' lost glory. Darkwill's allies, a mysterious cabal known as the 
Black Rose, reanimated the long-dead hero using forbidden magics, and presented him to the Grand General. After a few battles, Sion's blood lust was deemed uncontrollable and Boram ordered for his imprisonment. Hundreds of warriors died trying to restrain him before he was finally bound in chains and dragged back to the 
Immortal Bastion. Without slaughter, the blood magic that sustained him quickly engulfed his mind in an all-consuming rage. His roars finally fell silent as he was sealed in beneath his giant statue.
Trivia
- 917 AN - 940 AN
Camille becomes Clan Ferros' Principal Intelligencer.
