Siege of Angband

The Siege of Angband was the name given to a 400 year-long Noldor containment of Morgoth's forces within his fortress of Angband during the First Age, which began following the Dagor Aglareb. Though called a siege, this containment was not technically a siege at all as the Elves and Edain were unable to actually assault Angband; they were merely able to battle Morgoth's Orcs when they chose to emerge.