Esham was a member of the Council of Wizards who held the rank of “Wizard” under the Mage Celí Mará. He died in a tragic accident triggered by the change of magic in 1108.
Esham's areas of research were the Outer Planes and Extra-Dimensional Magic. He built a fortress in the Sea of Sand far away from civilization so that he could safely explore these other realms. However, when the magic changed in early 1108, many of the safeguard spells that he had erected fell – and his castle became a miasma of terror as alien dimensions burst through. he managed to send a magical warning message to the Council, but by the time anyone got there, it was determined that nobody could have survived.
When the Council finally convened in the Spring of 1108 to discuss the magic change, they issued an edict warning all people to avoid the fortress as “the risk of infection from other realms is too great”. The Wizard [Khranalda]] was tasked with casting wards around Esham's fortress and erecting warning signs – though it is unclear if she succeeded in this endeavor.
At the time of the magic change, Esham had numerous “observation” portals open to other planes of existence. When the magic changed, these portals lost their protections. Most failed entirely, but some turned into two-way portals, allowing some extra-planar creatures to enter this world.
Esham was able to contain most of the incursions, but in the end, he was overwhelmed. The most serious incursion was of a powerful alien sorcerer named “Acererak”. His origin is unknown, but he arrived in this world with his own reality and was able to reshape Esham's castle using only his will. The end result was an insane death trap known as “The Tomb of Horrors”.
When Acererak reshaped reality around Esham's castle, he also reshaped Esham himself. The primary effect of this alteration was that Esham gained “Far Sight” – a special sense which allows him to sense not only the reality around him but also that in nearby planes and dimensions (and even through time).
With his new “Far Sight” ability, Esham saw the universe in a new way and decided that he needed to correct its manifest flaws. He used his magic to leave evidence that he had perished and left the area for parts unknown.
Sometime over the next decade, he adopted the persona of “The King in Yellow” and recruited an elite group of followers which he dubbed “The Four Courts”. His first group of followers was disrupted by a group of adventures known as “The Agents of Fortune” in the year 1122. In response to this disruption, he dissolved the courts and went into hiding.
After a few years, though, he reformed the courts and slowly began a new campaign to exert his will over the universe. At present, the details of this campaign and the King's true motivations remain a mystery.