Although Turgon was originally against the departure of the Noldor from Aman, he eventually did set out on the journey. After Fëanor and his sons departed using the only ships, he took his people across the dangerous Helcaraxë with his father Fingolfin. He lost his wife Elenwë in the crossing and settled at Vinyamar in Nevrast. There he became lord of a mingled people, both Noldor and Sindar.
While he was journeying with his cousin Finrod Felagund along Sirion, Ulmo sent both of them a dream to look for a hidden place where they could be safe from the power of Morgoth. In the following year Ulmo appeared directly to Turgon and guided him to the vale of Tumladen in the Encircling Mountains, to which Turgon later secretly moved, taking with him a third of the original followers of Fingolfin and many of the Sindar, deserting Nevrast, and building the city of Gondolin. The disappearance of so many of their brethren led many Elves to search for the "Hidden Kingdom" of Turgon.
Turgon and his people remained isolated in Gondolin for many years, and he had a daughter, Idril Celebrindal, who married Tuor after the man was guided to the secret entrance by dreams from Ulmo. Tuor's coming had long been prophesied by Ulmo, who had instructed Turgon to leave a suit of armour in Nevrast for a future messenger, which turned out to be Tuor. Tuor's warning of doom was ultimately rejected by Turgon, who trusted still in the secrecy of his kingdom, and the vigilance of his allies, the Eagles, who prevented any spies of Morgoth from finding it.
Turgon re-emerged with his host during the Nírnaeth Arnoediad, and although the battle was still lost, his intervention prevented the rout from completely destroying the armies of the Noldor and their allies.
Turgon died defending Gondolin when it was betrayed by his nephew Maeglin, who desired Idril, and sacked by the hosts of Morgoth.
Turgon wielded the sword Glamdring which was later found and carried by Gandalf.