The Faelish Eruption of Faeland Island, also referred to as the Critical eruption or Valanian eruption, was a major catastrophic volcanic eruption with a Volcanic Explosivity Index (VEI) of 4 or 5 which is estimated to have occurred in the mid second millennium BCE. The eruption was one of the largest volcanic events on Earth in unrecorded history. The eruption fractured the island of Valania (also called Faeland, but here for clarity called by its scientific appellation), into three distinct islands and generated the coastline with which we are familiar today.
Scientists agree that three overlapping calderas formed the ancient shape of Valania or Faeland. With the eruption, quakes, and resulting lava flow and drowned valleys, the landmass was split into 3 distinct main islands.