According to Hesiod, Alecto was the daughter of Gaea fertilized by the blood spilled from Uranus when Cronus castrated him.
In Virgil's Aeneid (Book VII), Juno commanded the Fury Allecto (spelled with two l's) to prevent the Trojans from having their way with King Latinus by marriage or besieging Italian borders.
She disguises herself as Juno's priestess Calybe and appears to Turnus in a dream persuading him to begin the war against the Trojans.
Unsatisfied with her work in igniting the war, Allecto asks Juno if she can provoke more strife by drawing in bordering towns.
Juno replies that she will manage the rest of the war herself: "You're roving far too freely, high on the heavens' winds, and the Father, king of steep Olympus, won't allow it.