Origin
Discord, is the roman analogue of the Greek Goddess Eris. She is best known as the goddess, who on being snubbed by the gods on mount Olympus sought revenge by rolling a golden apple into among the inscribed “Kallisti” (To the Prettiest One) which led to a conflict between three goddesses about which one of them should get it. This led to Zeus passing the buck to the human Paris to make the choice, which eventually led to the Trojan War.
After this she appears in few other myths.
History
The goddess Discord/Discordia however has made quite a few appearances both in comics, in various adaptations of the Iliad, as a super heroine who sometimes helped Diana, the Huntress in her series in the 40s in Yellowjacket Comics, as a regular villainess (under a different name) at Marvel and DC, some independent comics written by Discordians (modern day “worshipers” of Discordia) and as a recurring animation character on the Grim Adventures of Billy and Mandy.