The ship's history prior to 2004 is unknown, but by the end of the year it had been deployed to Comberth Harbor with the rest of the Aegir Fleet. By November, the Independent State Allied Forces discovered the Tanager would be part of a planned strike on North Point to destroy the ISAF's GHQ. ISAF's subsequent interdiction missions made the task of refueling the fleet impossible, and many of its ships were stuck at anchor in the harbor. However, the Tanager was already refueled and set to make sail.
On November 23, 2004, the ISAF launched Operation Rough Seas with the goal of sinking the Aegir Fleet while it was vulnerable. At 1200hrs, the Tanager was sailing south away from the harbor when the ISAF strike force entered Comberth's airspace; the battleship was subsequently hit by missile fire from ISAF fighters and sank in the waters outside the harbor's entrance.
- The Tanager being a flagship is noteworthy since most flagships in modern, real-world navies are aircraft carriers, not battleships. However, during World War II, flagships were often chosen for their speed instead of their power. This could imply that the Tanager may have been faster than the Geofon, despite having less firepower.