After the attack of the Ettenmoors near Angmar, Hwaldar, the chieftain of the Rhudaur Hillmen was kept hostiled by the Arnorians. The Witch-King & his armies of Hillmen & Goblins march towards Rhudaur to destory any Arnorian warriors that lie on the hills. but Morgomir recognizes a valuable ally to control the Hillmen of Rhudaur. The Witch-king and his army eliminate the Loyalists and recruit the rebels. Soon after, they destroy the Dúnedain guarding Hwaldar and free him. They then proceed to attack the mighty Arnor fortresses in Rhudaur, but the attack (while successful on one fortress) weakens the Angmar forces badly and King Argeleb I soon arrives to finish them off.
Just as King Argeleb I was going to kill the rest, Kaltdrache comes & saves the remaining forces & kills Argeleb with his claws & flames. Morgomir brilliantly trains the Thrall Masters to replenish the Angmar army and wipe out King Argeleb's army. They then destroy the other fortress, claiming total control over Rhudaur & the Rhudaur Hillmen now have camps on their hills.