The War of Neystirium was a major event waged for three days between Neystirius, Aeling, the Faltmer, and Auren. It was a war of dominance over what Daedric prince shall maintain control over the Faltmer and decide their fate.
The war ended when Auren defeated his creators Neystirius and Aeling in the Daedric Plane of Neystirium. This event led to Auren destroying the Faltmer race and creating a Snow Elf-Altmer Hybrid race known as the Aucmerians.