The Kosscow Sea War was an 11-month war fought primarily on islands that divide Northern Europa's central seas, the Kosscow and the Ranke. Some international observers consider the conflict to be a theater of the Grand War, while Europan perspectives generally consider it to be a separate, coinciding conflict with origins in the Long War and Gaellicia's Silent War. The conflict began on 21 January 2023, when Volsci invaded Gaellicia in a surprise operation. The initial Volscian assault focused on the island of Yaran, which fell under Volscian occupation within the first few days of the war, and the southern portion of the island of Ailynlleth. Volscian forces advanced to their furthest extent in mid February, reaching the outskirts of the city of Beaumaris and landing troops on Gaellicia's largest island, Vanarambaion. After a successful Gaellician counterattack in April, Volsci expanded the scope of the conflict, invading the Hexanesa in June and drawing Tagmatium into the war.
