The subject of this article or section originates from non-canonical sources. To find out about what is considered "canon" see LOTR:Canon.
In the wars of the First Age, Tar Goroth was a general in Morgoth's army when the Dark Lord battled the Valar. After the defeat of the evil Morgoth, the spirit Carnán threw the Balrog at last in the fiery pits of the plains of Gorgoroth, where he now lies.
During the Third Age, the Darkness crept back within the land of Mordor. The forging of the Bright Lord's New Ring has awakened Tar Goroth from his slumber. This has not gone unobserved by Sauron himself, who commands Zog to sway the demon to his side. Rising from the molten fires of Gorgoroth, Tar Goroth proves too powerful for even Zog to tame. Despite the best efforts of Carnán and the Bright Lord, the shadowy menace is once again unleashed upon Middle-earth.
Following a trail of dead Orcs to Seregost, the Bright Lord and Carnán confront Tar Goroth once more upon a frozen lake. After a hefty skirmish, the two are able to bring down the Balrog and plunge it into the watery depths underneath the ice.