In Greek mythology, Tartarus is both a primordial deity and the deep abyss used as prison for the Titans and, later, as a place of torment for the wicked. Hesiod ranks personified Tartarus among the earliest beings after Chaos and Gaia; by Gaia he fathers Typhon. Homer and Apollodorus place the pit as far beneath Hades as heaven is above earth. Plato's Gorgias makes it the seat of posthumous judgment. This entry concerns the mythic abyss, not later Hell metaphors alone.
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I.Primordial deity and cosmology
In Hesiod's Theogony, Tartarus is the third primordial after Chaos and Gaia (before Eros). He is father, by Gaia, of the monster Typhon. Hyginus instead makes Tartarus offspring of Aether and Gaia. Cosmographically Hesiod measures the gulf: a bronze anvil would fall nine days from heaven to earth and nine more from earth to Tartarus. In the Iliad Zeus says Tartarus is as far beneath Hades as heaven is above earth; Apollodorus echoes the same scale.
Early use confines Tartarus mainly to dangers against the gods. Cronus imprisoned the Cyclopes and Hecatoncheires there under the guard Campe; Zeus killed Campe, freed them for the Titanomachy, then cast many Titans — and later Typhon — into the pit, with the Hecatoncheires as warders.
II.Prison of gods and sinners
Later myth expands Tartarus into a place of unique mortal punishments: Sisyphus rolling his stone, Tantalus forever reaching for fruit and water, Ixion bound to a flaming wheel, the Danaïdes carrying leaky jars, Tityos fed on by vultures, and others such as Salmoneus, Arke, and Phlegyas. Apollo threatens Hermes with Tartarus in the Homeric Hymn; Zeus nearly consigns Apollo himself for killing the Cyclopes.
Plato's Gorgias and related dialogues describe judges of the dead (Rhadamanthus, Aeacus, Minos) sending unjust souls to Tartarus — some for purification, the incurable as eternal warnings. Virgil's Aeneid elaborates Roman Tartarus with triple walls, the Phlegethon, a hydra-gated entrance, and Tisiphone on watch.
III.Later reception
Hellenistic Jewish and Christian texts reuse the name: Enoch places fallen Watchers under Uriel's charge in Tartarus; 2 Peter 2:4 uses the verb tartaroō ("cast into Tartarus") of sinful angels. Gnostic and pseudepigraphic works likewise know an abyss of Tartarus.
English "hell" translations sometimes flatten the distinction. This notice treats Greek and Roman Tartarus as deity and underworld prison within classical myth.