Based on events of Bethesda Softworks' The Elder Scrolls Lore.
In 270, Emperor Uriel Septim V of the Empire lays down plans to conquer the foreign continent of Akavir. By the late 280s, the Empire's Far East Fleet sails to Akavir and establishes Septimia and Ionith. The native Tsaesci swarms counter attack the intrusion into their lands, leading to the events known as the Disaster at Ionith.