These battles were seen in the video game, The Rise of the Witch-King
Foundations of Angmar
The Witch-king, Gorkil the Goblin King and Morgomir arrive at a barren land to the North near the Ettenmoors. They immediately notice a highly intelligent warrior troll, Rogash, and recruit him on the promise that they will reunite the Snow and Hill Trolls. The three Angmar Champions rush to the fighting Trolls, where the Witch-king fulfills his promise to Rogash and unites the Trolls. The Witch-king orders the foundation of three mighty Angmar fortresses while his armies eliminate the Black Númenóreans in the area, freeing other trolls in the process. Soon after, a great army of Black Númenóreans arrive to eliminate the intruders, but the Witch-king and his troll army easily crush them. The Witch-king forces the allegiance of the Black Númenóreans, and Angmar is successfully founded.
Assault on the Ettenmoors
The Goblins & Angmar set up camp in the snowy Ettenmoors. Elrond out that more Goblins were setting up camp in the Ettenmoors. He sent Rivendell's two heroes, Glorfindel, Glóin, Idrial & an army of Elves from Lothlórien & Rivendell to destroy Angmar at the Ettenmoors. Angmar founded that an army of Elves are going to attack the armies of Angmar & Goblins. After the camp was ready, a huge army of Goblins & Angmar are trained to battle. Soon the Elves will come to attack in two hours so the Goblins made the Ettenmoors Fortress stronger so it wouldn't be destroyed by the Elves. Then two hours has passed but before the battle can begin, five Rivendell Lancers came to the Ettenmoors gate. Trying to destroy the gate, Gorkil killed two of the Rivendell Lancers & so the Rivendell lancers joined in the army of Elves. The Elves charged & the combined evil armies charged at the Elves. More Elves are begining to get killed more because of the combined armies of Angmar & Goblins. Some Dwarves & Elves fleed back to Rivendell. Glorfindel & Glóin fleed with the others back to Rivendell. Idrial the archer came to fight Gorkil. As the Witch-King of Angmar helped out Gorkil killing her, Gorkil quickly picked up a Lorien archer's bow & shoot her in the right shoulder. Then quickly Gorkil sliced off Idrial's left arm & the Witch-King of Angmar wield his Morgul Blade & stabbed Idrial, falling dead in the snow. When Idrial was killed, Gorkil & the Witch-King continued on killing the rest of the elves of Lothlórien. After all of the Elves were killed
Fall of Rhudaur
A group of Hillmen of Rhudaur begin to rebel against Arnor, led by Hwaldar. Hwaldar is seized and arrested, 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. Morgomir brilliantly trains the Thrall Masters to replenish the Angmar army and wipe out King Argeleb and his army. They then destroy the other fortress, claiming total control over Rhudaur.
Invasion of Amon Sûl
Further invasions from Angmar are thwarted by King Arveleg I, who uses the Palantír of Amon Sul to foresee attacks. To proceed in Arnor's destruction, the Witch-king must destroy Amon Sûl and claim the Palantír.
Rogash, Hwaldar, Morgomir, and the Witch-king are all involved in this battle. The forces of darkness start off by destroying five Mallorn trees that power various defenses of Amon Sûl. After they are destroyed, they proceed in destroying the main fortress. Reinforcements of Arnor later arrive, but the enemy wipes them out completely. The Angmar forces turn back towards Amon Sûl and begin destroying the structures in the fortress despite heavy resistance. Angmar eventually summons two Mountain Giants and proceeds to attack the watchtower, destroying it once and for all.
Though Angmar has destroyed Amon Sûl, Arveleg has escaped with the Palantír. The Witch-King sends Morgomir to retrieve it.
Dark Lord's Eye
A small Angmar scout party sent by Morgomir pursues Arveleg. The Dire Wolves make a mad rush for King Arveleg, while the Thrall Masters summon Gundabad Orcs to attack the Tower Guards. The combined forces successfully wear down Arveleg, but before he is killed he smashes the Palantír, causing a huge explosion killing everything nearby.
Morgomir and more powerful forces later arrive and notice a shard of the Palantír, which is still filled with power. Arnor also notices it and sends orders to retrieve it. Angmar and Arnor compete and race for mastery of the shards, partially since both of their powers have been nullified by the blast and are regenerated with the Palantír shards. Angmar gets most of them, but when Arnor brings some to their outpost Morgomir and his forces destroy the outpost. After the Arnor outpost is destroyed, Morgomir easily gathers the seven shards and gains victory for Angmar.
Cardolan wasn't affected by the destruction of Amon Sûl so the Witch-king attacks the Barrow Downs, planning to draw out Cardolan's forces into a foolish and self-destructive charge. He sends Hwaldar to claim the royal barrow. To assist the conquest, Hwaldar destroys the attacking forces and kills some Dúnedain rangers that planned attack the reinforcements of Angmar. With him are some Thrall Masters and Sorcerers that have gained power from the Palantír shards. When Hwaldar reaches the Royal Barrow, Cardolan becomes enraged and sends its forces to destroy him. But, the Rhudaur Warriors hold back each attack and the Sorcerers cripple and destroy Arnor's soldiers, turning some of them into corrupted Wights. As time passes, more Sorcerers, Thrall Masters, and Trolls arrive; at one point, Morgomir & Drogoth the Dragon Lord joins the battle. In the end, the Prince of Cardolan himself arrives to answer the challenge, but so does the Witch-king and Rogash at the same time. The Prince is eventually killed by the Witch-King and his forces, and Cardolan is laid bare to the enemy.
Glorfindel, Elrond and the Elves prepare to lead a charge on the capital of Carn Dûm, in an attempt to destroy Angmar and give Arnor time to recover. The Witch-king lights a beacon to call Rogash, and some builders and Hwaldar begin setting up defenses. By the time the Elves attack, Carn Dûm is ready. Despite this, the battle originally goes ill for Angmar as more and more trebuchets and Elves pound on the assault. Just as Carn Dûm appears to be taken, Rogash and Morgomir arrive with armies of Trolls. With these powerful new reinforcements, Carn Dûm is saved from the Elves. Glorfindel is defeated, but before he can be killed he is rescued by the Elves (later to launch a more successful invasion of Angmar. He is also one of the heroes in the good campain on Battle For Middle Earth 2). In the meantime, however, Angmar is weakened but not destroyed, and the Witch-king continues to plan the next assault even as both Angmar and Arnor recuperate.
After an unsuccessful attack by Men and Elves on the fortress of Carn Dûm, the Witch-king contemplates his next move. The audacity of his enemies angered him greatly, and a example should be made. However, Angmar has been significantly weakened, and his next attack needs to be planned in order to prevent failure.
With the help of Morgomir, he decides to unleash a terrible plague upon the unsuspecting Arnor, created by his Black Numenorean sorcerers. These wicked men, already deeply immersed in the Dark Arts, have become even more powerful due to acquiring the shards of the Palantír; their powers have already been demonstrated in the Battle for Cardolan. However, the Witch-king needs a ground zero from which his diabolical plague will spread. With utter malice, he chooses the most sacred ground in all of Arnor: the Barrow downs. These quiet and dignified monuments of the Dúnedain are essential to the morale of Cardolan, which Angmar is perfectly aware of.
Morgomir is to lead the attack on the Barrow downs. Cardolan's forces, outraged at this desecration, sends its own armies (led by Captain Carthaen) to destroy Angmar's forces even as the Sorcerers begin corrupting souls. Morgomir, however, instructs his Sorcerers to cast their own terrible spells on the Cardolan army, weakening it significantly. To finalize victory, Morgomir summons a tortured, evil ice werewolf to crush the opposition. The Sorcerers complete the plague, and the Barrow-wights are fully created. Captain Carthaen is soon trapped by the Wights, and Morgomir stabs him with a Morgul-blade. And so, Karsh the Whisperer is created.
Angmar has almost completely dominated Arnor, but Fornost still remains to be taken. The Dúnedain and their allies all gather for this final assault. In order to prevent a foolish advance (and subsequent destruction), the Witch-king prepares a base and gathers his forces first. After all the preparations, they begin the assault. Angmar starts by destroying the front gate and some of the outer defenses. Combining the fury of the Angmar army and deadly Angmar ice powers, the Witch-King slowly wears down the fortress one building at a time. Casualties are both sides are high as the Dúnedain desperately battle for their lives and Angmar's army fights in a berserk rage. In the end, the citadel of Fornost is destroyed and the structure falls. Angmar has achieved complete victory over Arnor, and has now opened the opportunity for complete domination of the North.