In The Iliad and The Odyssey, why were they defeated? (Trojan War)
This question is a bit vague. So, I will give an basic explanation of the Trojan War. The Trojan war was between the Trojans and the Greeks. As the story goes, The Trojan prince, took Helen of Sparta as his wife. This enraged Helen's husband, Menelaus. So, Menelaus and his brother Agamemnon gathered the Greeks to sail against Trojan. The war was ten long years and just as the Trojan were about to win, Achilles goes into the battle to destroy the Trojan hero, Hector. In addition, Odysseus comes up with a ploy to offer a wooden horse to the Trojans and feign flight. Unknowingly, the Trojans take in the horse, which was filled with Greeks, into their city. This proves to be their demise. The Greeks win.
So are you asking why the Trojans were defeated? That is the question I will answer.
The Trojans were defeated because of a trick played by Odysseus (some say the goddess Athena helped him). He had the Greeks build a huge hollow horse (the famous Trojan horse) and leave it outside of Troy. Then the Greeks all sailed away.
The Trojans came out and took the horse back inside the city. The horse was full of Greek warriors. That night, they came out of the horse and killed the Trojan warriors.