Eris mad that she didn't get invited to Zeus wedding because she is gonna start a conflict.
So she's going to the wedding with a golden apple.
Eris said the golden apple goes to the Fairest and so Three olympian goddesses Hera (queen of gods), Athena (goddess of wisdom and war, And Aphrodite(goddess of love and buity.
Zeus chose someone to judge someone random and did not know much about the goddesses so he picked a boy named Paris Each goddess made Paris an offer Hera (queen of gods) would make him ruler of the world, Athena (goddess of wisdom and war) offered him to victory in war, And Aphrodite(goddess of love and beauty. preposed to promise that he would marry the most beautiful woman on earth.
Paris picked Aphrodite so he would have to marry Helen the wife of the Greek king Menelaus Paris had Helen taken away from the pales of Menelaus in Sparta. Which invoked the oath of Tyndareus, requiring the united powers of the Greeks to avenge the wounded honor of Menelaus and retrieve Helen. The Greeks traveled to Troy and for nearly ten years, the Greeks unsuccessfully besieged Troy in the Trojan War.
Finally, the Greek warrior, Odysseus, had the idea to build a large wooden horse, known as the Trojan Horse. The Greeks hid warriors inside the horse and left it at the gate of Troy. Meanwhile, they pretended to sail away. That night the Trojans took the Horse into their city and the warriors crept out and threw open the city's gates. The Greeks entered, sacked the city, and claimed a victorious end to the great Trojan War.