Alagiel was the mother of Voronwë Aranwion , and the wife of Aranwë. She was a Sinda elf of the Falas who was a kinswoman to Cirdan the Shipwright. Alagiel met Aranwë in Vinyamar and eventually went with him to Gondolin.
During the events of the Fall of Gondolin, it has been surmised that she went with her husband and son. After managing to escape the destruction of Gondolin, Alagiel moved to Lindon and lived with her husband and uncle, Cirdan.