During the War between the Latins and the Trojans (along with several other Trojan allies, including King Evander's Arcadians), Turnus proves himself to be hot-headed but brave. In Book IX, he nearly takes the entire fortress of the Trojans after defeating many opponents, but is saved from death by Juno.
In Book X, Turnus slays the son of Evander, the young prince Pallas. As he gloats over the killing, he takes as the spoil of war Pallas' sword belt and puts it on. Enraged, Aeneas seeks out the Rutulian King with full intent of killing him. The narrator of the Aeneid marks the death of Pallas by mentioning the inevitable downfall of Turnus. To prevent his death at the hands of Aeneas, Juno conjures a ghost apparition of Aeneas, luring Turnus onto a ship and to his safety. Turnus takes great offense at this action, questioning his worth and even contemplating suicide.
In Book XII, Aeneas and Turnus duel to the death; Aeneas gains the upper hand amidst a noticeably Iliad-esque chase sequence (Turnus and Aeneas run around the lines of men several times, similar to the duel of Achilles and Hector). Turnus begs Aeneas either to spare him or give his body back to his people. Aeneas considers but upon seeing the belt of Pallas on Turnus, he is consumed by rage and finishes him off. The last line of the poem describes Turnus' unhappy passage into the Underworld.
Turnus' supporters included Latinus's wife, Amata, Juturna, his sister and minor river/ fountain deity, Mezentius, the deposed king of the Etruscans, and Queen Camilla of the Volsci, who helped him fight Aeneas.