Those that bore this cursed mark rose again after death until eventually their mind shattered and they become hollow. The plague of undead contributed heavily to the instability of Gwyn's reign, and their were whispers of a dark prophecy made by a great serpent of the abyss. The prophecy claimed that a chosen undead would one day defeat Gwyn and take his place.
The once beautiful city of New Londo had fallen into darkness, the four wise kings that once served Gwyn seduced by a serpent's gifts. As the abyss rose to claim swallow the city and those who lived there became twisted with dark power, Gwyn decided to flood the place and drown all those within, though it is said their ghosts still haunt the ruins.
The witch of Izalith and her many daughters attempted to use sorcery to recreate the first flame, but the result was a complete disaster. The flame she created was chaotic and uncontrollable – her realm was twisted into a hellscape and the residents into monstrous demons. Even the witch and her children were horribly changed. Gwyn decided to lead his silver knights against the demons, but they were scorched black and forced to retreat.
Troubled by Gwyn's indecision, the All-Father Lloyd (uncle to Gwyn and the leader of his church) began to recruit followers to join his order of paladins. He blamed the undead for the dying flames, and believed that by hunting them down and imprisoning them he could prolong the Age of Fire. However soon undead began to be born even into the most powerful aristocratic families of Thorolund, and Lloyd's mandate to destroy the undead became unpopular.
Lloyd decided that those that were undead or that challenged church dogma such as Gwyn's divinity should purify their faith by going on holy crusades. Paladins led undead prisoners and heretics on various missions to find artefacts such as the Rite of Kindling which might hold the solution to Gwyn's difficulties.
Though most Thorolunder crusades were to the cursed land of Lordran in search of the Rite of Kindling, some paladins had wilder ideas about what the answer to Gwyn's delimna was and where it might be found.
A few hundred years before, the paladin Janus of Thorolund had led an expedition across the sea to a strange and barren continent. He claimed to have been sent visions of a city wrought of gold where the power to end the curse was hidden. Following his mysterious convictions he delved into the earth, and later began to deliver valuable titanite ore to Thorolund by ship. However after a few years no word was heard from Janus, and his expedition was forgotten.
It was not remembered again until the All-Father Lloyd was faced with the difficulty of disposing of troublesome undead and seeking a way to restore the first flame. Though many believed that the invaluable treasure Janus had been searching for was merely titanite, Lloyd reasoned that if undead had even the faintest chance of serving Gwyn then such a task would be a great honour for them.
He ordered paladins to load ships with undead prisoners and sail them to the place where Janus had commenced his excavations. Some of the paladins went into the underground tunnels first, to find out what was left of Janus' headquarters, but they did not return. Becoming uneasy, the remaining paladins ordered many of the undead inside, but they did not return either.
At this point the remaining undead and paladins began to dread the gaping entrance that horses were unwilling to approach, and called it the Pit of Certain Death. The paladins themselves would not enter now, instead ordering groups of undead inside until only five undead remained.
Each of the undead looked around at his four companions, hoping to see powerful allies that might protect him from danger, but each was disappointed. The paladins ordered them inside, sealed the gate behind them, and sailed away from that unpromising land.