In Greek mythology, Deiphobus was a Trojan prince, son of Priam and Hecuba, and after Hector the greatest of Priam's sons. In the Iliad Athena borrows his likeness to lure Hector into facing Achilles; after Paris's death he marries Helen, defeating his brother Helenus's claim. He dies in the sack of Troy — slain by Menelaus or Odysseus in most accounts — and appears horribly mutilated to Aeneas in Virgil's underworld.
Adapted from Wikipedia, "Deiphobus" · CC BY-SA 4.0
I.Warrior in the Iliad
With Helenus, Deiphobus leads troops against the Achaean wall, kills several Greeks, and wounds Meriones. When Hector flees Achilles, Athena takes Deiphobus's shape and voice and persuades Hector to stand and fight, promising to fight beside him. Hector, calling him the dearest of Hecuba and Priam's sons, throws his spear; when he turns for a second lance, the false brother has vanished — and Hector knows the gods have abandoned him.
Priam later names Deiphobus among surviving sons when he chides them before ransoming Hector's body. Late chroniclers (Malalas, Dares) give physical portraits; Hyginus and Dictys involve him with Paris in the ambush that kills Achilles at the interview over Polyxena.
II.Helen and the sack
After Alexander (Paris) dies, Deiphobus and Helenus quarrel for Helen's hand; Deiphobus is preferred and Helenus withdraws to Ida. Euripides' Trojan Women treats the marriage as forced. In the Odyssey, Helen walks around the Wooden Horse calling the hidden chiefs in their wives' voices while godlike Deiphobus follows; Menelaus and Odysseus restrain the men inside from answering.
During the sack, Odysseus and Menelaus storm Deiphobus's house in Demodocus's song — the fiercest fight of the night. Apollodorus has Menelaus kill him and lead Helen to the ships; Hyginus grimly lists Helen herself among wives who slew their husbands. Virgil's Aeneid shows his mutilated shade in the underworld, blaming Helen for signaling Menelaus to the bedchamber and begging the gods for revenge on the Greeks.
III.Reception
Deiphobus remains a minor figure in Shakespeare's Troilus and Cressida and occasional modern retellings. The asteroid 1867 Deiphobus commemorates the Trojan prince. This notice concerns Priam's son, not other rare uses of the name.