During the sack of Gondolin, Tuor defended Idril and their only child Eärendil from Orcs and the traitorous Maeglin, who was promised both Gondolin and Idril by Morgoth in return for the location of the hidden city and threatened to murder the child by throwing him over the edge of the city wall. After Maeglin's death, they led a remnant of the people of Gondolin to escape the sacking of the city by Idril's Secret Way, but encountered in the mountain heights a Balrog, who was defeated by the valour and self-sacrifice of Glorfindel, chief of the House of the Golden Flower. They eventually reached Nan-tathren and the Mouths of Sirion.