Battle of the Plains

The Battle of the Plains is where King Narmacil II of Gondor and Marhari leader of the Northmen, combined their forces in order to stop the rushing advancement of the Wainriders under Rhun and Khand. The battle was terrible as both of the west's leaders were killed and the remnants of their army retreated which then allowed the Wainriders to take over Rhovanion (including occupying Dorwinion).