First Age 510

• (Early Summer): Fall of Gondolin. Resulting deaths of Turgon, Ecthelion of the Fountain, Glorfindel of the Golden Flower, Maeglin, Penlod of the Pillar and the Tower of Snow, Duilin of the Swallow, Rog of the Hammer of Wrath, Gothmog, Lord of Balrogs, Orcobal, Balcmeg, Othrod, Lug, and possibly Salgant of the Harp.
• Ereinion Gil-galad becomes High King of the Noldor

References

• The Book of Lost Tales Part 2, The Fall of Gondolin