Siege of Angband

The Siege of Angband was a 400-year long standstill between the Noldor and Morgoth's fortress of Angband, starting after the Glorious Battle.

Though long-lasting, the siege was ineffective as the mountain range of the Thangorodrim prevented the Noldor from sieging the fortress directly, but rather forcing them to hold the various passes through the mountains.

In the middle of the siege, Morgoth struck out with his forces, but was defeated and had to retreat back to Angband. Thus started the Long Peace.

The siege held until the Battle of Sudden Flame, when Morgoth explosively stuck out and conquered the siege-laying forces of the Noldor.