Eris was the Greek goddess of chaos, strife and discord. She was the daughter of Zeus and Hera; according to other myths, she was the daughter of Nyx (dark night) alone. Her opposite was Harmonia. The equivalent Roman goddesses of Eris and Harmonia were Discordia and Concordia. She had a son, Strife, whom she brought along with her when she rode her chariot to war alongside Ares.
Eris played an important role in the events that eventually led to the Trojan War. All of the Olympians had been invited to the wedding of Peleus and Thetis, who would become the parents of Achilles; however, Eris was not invited, due to her inclination to cause discord.
As a means of revenge, Eris dropped the golden Apple of Discord into the party, which had the words To The Fairest One inscribed on it. Hera, Athena and Aphrodite started quarreling over who the apple should be given to, so Zeus appointed Paris, Prince of Troy, as the person to solve the dispute. The goddesses offered Paris various gifts, but he eventually picked Aphrodite, who promised him the most beautiful woman in the world; Helen, wife of Menelaus, king of Sparta. This led to the Trojan War and the distruction of Troy.
Polytekhnos and Aedon claimed to love each other more than Hera and Zeus. This angered Hera, who sent Eris to punish them. Polytekhnos was working on a chariot board and Aedon was weaving. Eris urged them into a competition by proclaiming that whoever finished last would have to give the other a female servant. Aedon won and Polytekhnos was not happy by his defeat. He went to Aedon's sister Khelidon and raped her. He then disguised her and presented her to Aedon as a slave. When Aedon discovered this, she killed Polytekhnos's son and feed the boy to his father. The Gods were not happy and tranformed the whole family into birds to stop this.