Siege of Angband
The Noldor and their allies possessed insufficient force to assault Angband directly. Fingolfin and Fingon kept watch from Hithlum, Finrod and then Orodreth from Tol Sirion, Angrod and Aegnor from Dorthonion, and the Sons of Fëanor watched the east. The period during the Siege was known as Long Peace.
After about four hundred years, the Siege was broken in the Dagor Bragollach.