The destruction of the hidden Elven city of Gondolin during the First Age, one of the most tragic events in the wars against Morgoth. Gondolin was the last and greatest of the Noldorin kingdoms of Beleriand, hidden in a mountain valley for centuries. It was betrayed to Morgoth by Maeglin and assaulted by Balrogs, Dragons, and vast hosts of Orcs. Tuor and Idril led a remnant of survivors to safety, among them their son Earendil.