The charr were in Tyria first and ran wild over the entire continent. When the humans arrived, they were the first serious challenge to charr supremacy in centuries. But if it hadn't been for the death of the Khan-Ur, the humanity might not have survived those ancient days. The Khan-Ur's children, who were also his four imperators—leaders of their own personal legions—fell to squabbling over his mantle, each accusing the other of treachery. They set their legions against each other. Blood, Iron, Flame, and Ash. None of them were strong enough to defeat the other three, though, and in the course of the war, the Claw of the Khan-Ur was lost. Yet, their internal dissension gave humanity some breathing room to develop, and with that time they conquered Ascalon.
Several generations later, when the charr got their act together, the humans fought to keep them out of what they now considered to be their land. To that end, the kings of Ascalon began building a massive wall that ran west from the Shiverpeaks all the way to the Blazeridge Mountains on the Eastern Frontier. It took nine hundred years to complete, but it kept the charr north of it. Indeed, backed by the strength of the wall, they pushed them even further north, so that for most Ascalonians the charr were a distant but always present threat.
The Northern Wall stood unbreached for nearly two hundred years, but way back in 1070, the charr discovered a great magic, based on mighty cauldrons filled with mystic energy. The charr shamans, in particular those that commanded the Flame Legion, unlocked the secrets of the cauldrons and brought about the Searing. Great burning crystals fell from the sky and scourged the lands around them, breaking the Great Northern Wall.
The charr flowed through the wall in an unstoppable wave that washed all the way through Ascalon until it crashed on the shores of Orr. In Orr, its most powerful vizier cast a forbidden spell of his own that stopped the charr cold, but at the sacrifice of his entire nation, sinking Orr beneath the sea.
The Searing forced King Adelbern to move his capital from Rin to Ascalon City, the only major city in his nation that still stood. There, he felt, he would make his last stand against the charr invasion.
The king's sole heir, Prince Rurik, disagreed with him and led a large portion of his people over the Shiverpeaks to safety in Kryta rather than wait for their doom with their king. Prince Rurik never made it to Kryta with his followers: he gave his own life so that they might find their freedom. It is said that Prince Rurik's death hurt King Adelbern worse than the fall of Rin itself.
Back in Ascalon City, the Flame Legion prepared for a final assault on the place's walls. The imperator of the Flame Legion somehow got his hands on the Claw. The Claw is a powerful weapon, a force that would allow one to unite the legions under a single banner. But the other legions have to be convinced to earn the title of Khan-Ur. The Flame imperator believed that conquering Ascalon and beheading King Adelbern with the Claw would allow him to cement his claim.
The legions, led by the shamans of the Flame Legion, assaulted the walls of Ascalon City with their forces, their tamed siege devourers, and their magical cauldrons. The charr armies overran the defenders and surmounted the walls. Adelbern fought until the last, armed with his great magical sword, Magdaer. Magdaer was an ancient artifact from Arah, the City of the Gods, and infused with power. It is said that Magdaer's twin, Sohothin, was in the hands of his son, Rurik, when he died. In any event, Adelbern single-handedly brought down wave upon wave of charr warbands, making his last great stand on the battlements of his own tower.
The Flame Legion and charr surrounded Ascalon City for a final assault and managed to breach the city's defenses. King Adelbern's soldiers, seeing how the charr had the upper-hand, wanted to retreat but the mad Sorcerer-King refused. He shouted "We will never surrender! Never!" and plunged his sword Magdaer into the stones beneath him. A mystic light appeared where the sword had struck and eventually burst, spreading all throughout Ascalon. An event know as the Foefire .
The buildings, farms, and land were unharmed but every charr within its reach was destroyed. The humans, however, suffered a different fate. Their souls were peeled loose from their shredded bodies and they survive eternally as guardian ghosts that jealously protect the land. With the assistance of his cursed magic, King Adelbern finally managed to defeat the charr and doomed his people for eternity.