Ruin of Beleriand

(1) Barad Eithel withstands the attack in the west; (2) A force breaks through the Pass of Aglon, and Dorthonion is captured; (3) Maedhros survives the attack in his fortress on Himring; (4) Caranthir's fortress on Rerir is overrun, and he flees south; (5) Two years after the main battle, Minas Tirith is captured by Sauron.

The destruction and war that came with the Dagor Bragollach and the breaking of the Siege of Angband. On a winter's night in the year I 455, without warning of any kind, Thangorodrim erupted with rivers of fire that ran out across Ard-galen. Glaurung the Dragon emerged, followed by Balrogs and armies of Orcs beyond count. The Siege that had lasted for nearly four hundred years was broken, and the forces of Morgoth fought back the defenders of Beleriand.

By the following spring, Morgoth held most of the northern marches of Beleriand, and within two years Sauron had captured the fortress of Minas Tirith that guarded the Pass of Sirion. The Elves had believed that they held Morgoth at bay during the Siege of Angband, but after the sudden flame of the Dagor Bragollach, the remaining history of the First Age was one of long defeat for the Eldar and Edain, until they were driven back to a final refuge at the Mouths of Sirion.

For all his strength, Morgoth was not to achieve final victory. From the Mouths of Sirion, Eärendil journeyed to Valinor to beg for aid from the Valar, and the Valar answered. Their forces came out of the West and fought the War of Wrath against Morgoth's armies. Though Morgoth was ultimately defeated, Beleriand was not saved from ruin: that cataclysmic war broke the land and drowned it beneath the Sea, so that only a narrow fringe of shore and a scattering of islands survived west of the Blue Mountains in later ages.