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The First Battle of Ione's Oblivion Gate took place around the height of the Oblivion Crisis. During the Daedric invasion, most of the Legions had been dispatched to the provinces to defend against the Daedra. Ione's company was recalled to Cyrodiil from the south to help fortify the Imperial City against attack. While passing through the West Weald, an Oblivion Gate opened directly in the middle of the company, taking the Legionnaires off guard. Daedra poured out of the Gate and fell upon the soldiers, killing the commander and half the company before a lone captain by the name of Tertius Ione gathered the survivors and forced a retreat. Shortly thereafter, Ione would return to lay siege to the Gate.