An old, mortal King, Peleus, falls in love and eventually marries the sea goddess Thetis. The goddess of discord - Eris - wasn't invited so she gets angry and delivers a golden apple labelled 'to the fairest'
Three goddesses -Athena, Hera and Aphrodite -want the apple so they come to a farm boy -Paris who is a Prince abandoned as a baby because his parents were told that he was going to bring disaster to Troy. He chooses Aphrodites for her promise of the most beautiful women in the world and the other goddesses hate Paris since he didn't choose them. Aphrodite delivers Paris home to his parents who welcome him in, forgetting about the Prophesy
The most beautiful woman in the world, a Greek named Helen, who Paris was promised marriage to by Aphrodite, had already chosen a husband for herself in a man named Menelaus.
After Helen had a child with her husband, Aphrodite organised with Paris to meet Helen so she could fall in love with him. This worked, and Paris stole Helen away with him back to Troy.
Every man who hadn't been chosen as Helen's husband pledged to protect her marriage at any cost. So when Helen went off with Paris, all the Greek men went over to Troy to get Helen back. Greece's best fighter- Achilles- was invincible except for his heel. He brought morale for the soldiers so they could fight but stopped fighting once the leader of the Greeks- Agamemnon- stole his slave girl to replace his own
Paris' brother, Hector, kills Patroclus who dressed up in his friend Achilles armour to scare the Trojans and gives the Greeks courage since Achilles was no longer fighting. After seeing what Hector did to his best friend, Achilles gets back out to fight and seek vengeance for Patroclus' death. Achilles eventually kills Hector outside Troy's wall. Seeing his brother dead, Paris begins to regret what he has done and Helen feels guilty for the countless deaths she has caused. After parading Hector's body around to the Greeks, the Trojan King wanted his son's body so Achilles gave in and handed it over. A little while later, Achilles is killed by an arrow that lodges itself into his heel.
The Greeks think up a plan to get themselves inside the heavily fortified Trojan walls which is to leave a giant wooden horse (filled with hidden Greek soldiers) as a gift for Troy as a peace offering. Their idea works as the Trojans buy the fact that this is a present from the enemy and won't do them any harm. Once they have checked the area has been abandoned of any Greek soldiers, they take the horse and a soldier that was left behind as another gift, inside the walls. That night, the soldier signals for the ships to turn around, opens the city gates and lets out the Greek soldiers who were hidden inside the horse who take Helen, sack the city and burn it to the ground.