The Taint was released upon Lusternia when Project Cosmic Hope, initiated by Emperor Ladantine VII and supported by a majority of the Basin's top officials and leaders, uncovered the Astral Plane. There, the Emperor attempted to channel energy from a mysterious pillar of crystal, which quickly grew unstable and corrupted the Stone of Truth, the Nexus of Power that the expedition was linked to. This caused a foul cloud of thick, black smoke to rise from the cracked Nexus on the Prime Material Plane, which quickly spread throughout the Basin and twisted and corrupted all that it touched.
When the Taint infected mortals, they either transformed into one of the undead, or underwent an intense physical transformation and became insane and out of touch with reality. The Taint had similar effects upon the physical landscape that it reached, as evidenced by the corruption of the Crystal Sea, which became the Sea of Despair, as well as the Gloriana Preserve, which became the Glomdoring Forest. Aeromancers in Hallifax attempted to defend their city with powerful gusts of wind, which slowed the northern movement of the cloud but sent it further south, infecting the Gloriana.
Conflict between those touched by the Taint and the rest of the Basin became known as the Taint Wars.