The war began after Celebrimbor discovered Sauron's treachery in the forging of the Rings of Power, and Sauron decided to crush the now implacably hostile Elves. The Three Rings were hidden by the Eldar, but in 1697 Eregion was overrun and Celembrimbor was slain. Elrond, who had been sent to Eregion by Gil-galad, fled with the remaining Noldor and founded Rivendell.
In the next two years Sauron overran all of Eriador except for Rivendell. Gil-galad asked Tar-Minastir of Númenor for aid, and in 1700 the latter sent a navy to Middle-earth with whose aid Sauron was defeated. In 1701, he was driven out of Eriador and the war ended.
Aside from greatly reducing the power and numbers of the Eldar, the war ended the only close link between the Elves and the Dwarves - the friendship between Khazad-dûm and Eregion.
Battles during the War of the Elves and Sauron:
- Foster, Robert. The Complete Guide to Middle-earth.