Understand how the last stronghold of the Noldor fell and why betrayal from within proved more terrible than a siege.
Chapter guide
The ruin of the hidden city
Gondolin is King Turgon's secret city, ringed by the mountains of the Echoriath, the fairest and most impregnable of the Elven kingdoms. Morgoth has long been searching for it (that is why he tortured Húrin).
Tuor, a Man, Túrin's cousin (son of Huor), is sent as a messenger by the Vala Ulmo, lord of waters. Ulmo guides him to Gondolin with a warning: the city must either prepare for war or leave. Turgon, loving his city, ignores the counsel to leave. Tuor stays and marries Turgon's daughter, Idril. Their son is Eärendil, Half-elven, in whom the kindreds of Men and Elves are joined.
The city is betrayed by Maeglin, Turgon's nephew. Taken captive, out of fear and his lust for Idril, he reveals the secret way to Morgoth. Morgoth hurls Balrogs, Orcs, and dragons at Gondolin. The city falls; Turgon dies in his tower. In the battle Glorfindel slays a Balrog at the cost of his own life. Tuor, Idril, and little Eärendil escape by a secret tunnel that Idril had wisely ordered dug, and go down to the Mouths of Sirion.
Lesson notes
The ruin of the hidden city
Gondolin is King Turgon's secret city, ringed by the mountains of the Echoriath, the fairest and most impregnable of the Elven kingdoms. Morgoth has long been searching for it (that is why he tortured Húrin).
Tuor, a Man, Túrin's cousin (son of Huor), is sent as a messenger by the Vala Ulmo, lord of waters. Ulmo guides him to Gondolin with a warning: the city must either prepare for war or leave. Turgon, loving his city, ignores the counsel to leave. Tuor stays and marries Turgon's daughter, Idril. Their son is Eärendil, Half-elven, in whom the kindreds of Men and Elves are joined.
The city is betrayed by Maeglin, Turgon's nephew. Taken captive, out of fear and his lust for Idril, he reveals the secret way to Morgoth. Morgoth hurls Balrogs, Orcs, and dragons at Gondolin. The city falls; Turgon dies in his tower. In the battle Glorfindel slays a Balrog at the cost of his own life. Tuor, Idril, and little Eärendil escape by a secret tunnel that Idril had wisely ordered dug, and go down to the Mouths of Sirion.
Betrayal, hope, and threads to “The Lord of the Rings”
Betrayal from within. An impregnable city cannot be taken by storm; it is undone by a kinsman's treachery. Maeglin is a dark figure: son of Eöl (“the Dark Elf”) and Aredhel, possessed by a forbidden love for his cousin Idril. The motif of “a fortress that falls through a traitor at the gates” will echo through the whole legendarium.
Glorfindel and the Balrog. Glorfindel's duel with a Balrog in the mountains is a direct parallel to Gandalf's fight with the Balrog of Moria in “The Lord of the Rings.” What's more, the very Glorfindel who meets Frodo at the Bruinen is, as Tolkien later conceived it, this same hero, returned from the Halls of Mandos and sent back to Middle-earth.
The birth of hope. The key event is the birth of Eärendil to Tuor and Idril. In him the blood of the House of Hador (Men) and the line of Fingolfin (Noldor) meet. It is Eärendil (chapter 24) who will sail to Valinor to plead for help. The fall of Gondolin is terrible, but out of its ashes escapes the one who will bring salvation to all of Middle-earth.
Ulmo is the Vala who did not abandon Middle-earth; through waters and dreams he alone of the Valar goes on helping Elves and Men when the others have withdrawn.