<P> Metaphorically a "Trojan Horse" has come to mean any trick or stratagem that causes a target to invite a foe into a securely protected bastion or place . A malicious computer program which tricks users into willingly running it is also called a "Trojan horse" or simply a "Trojan". </P> <P> The main ancient source for the story is the Aeneid of Virgil, a Latin epic poem from the time of Augustus . The event is also referred to in Homer's Odyssey . In the Greek tradition, the horse is called the "Wooden Horse" (Δούρειος Ἵππος, Doúreios Híppos, in the Homeric Ionic dialect). </P> <P> According to Quintus Smyrnaeus, ulysses thought of building a great wooden horse (the horse being the emblem of Troy), hiding an elite force inside, and fooling the Trojans into wheeling the horse into the city as a trophy . Under the leadership of Epeius, the Greeks built the wooden horse in three days . Odysseus's plan called for one man to remain outside the horse; he would act as though the Greeks had abandoned him, leaving the horse as a gift for the Trojans . An inscription was engraved on the horse reading: "For their return home, the Greeks dedicate this offering to Athena". Then they burned their tents and left to Tenedos by night . Greek soldier Sinon was "abandoned", and was to signal to the Greeks by lighting a beacon . In Virgil's poem, Sinon, the only volunteer for the role, successfully convinces the Trojans that he has been left behind and that the Greeks are gone . Sinon tells the Trojans that the Horse is an offering to the goddess Athena, meant to atone for the previous desecration of her temple at Troy by the Greeks, and ensure a safe journey home for the Greek fleet . Sinon tells the Trojans that the Horse was built to be too large for them to take it into their city and gain the favor of Athena for themselves . </P> <P> While questioning Sinon, the Trojan priest Laocoön guesses the plot and warns the Trojans, in Virgil's famous line Timeo Danaos et dona ferentes ("I fear Greeks, even those bearing gifts"), Danai (acc Danaos) or Danaans (Homer's name for the Greeks) being the ones who had built the Trojan Horse . However, the god Poseidon sends two sea serpents to strangle him and his sons Antiphantes and Thymbraeus before any Trojan heeds his warning . According to Apollodorus the two serpents were sent by Apollo, whom Laocoon had insulted by sleeping with his wife in front of the "divine image". In the Odyssey, Homer says that Helen of Troy also guesses the plot and tries to trick and uncover the Greek soldiers inside the horse by imitating the voices of their wives, and Anticlus attempts to answer, but Odysseus shuts his mouth with his hand . King Priam's daughter Cassandra, the soothsayer of Troy, insists that the horse will be the downfall of the city and its royal family . She too is ignored, hence their doom and loss of the war . </P>

Who had the idea of the trojan horse