The Battle of Cheron was the final battle of the Earth-Romulan War, fought around 2160. It was a crushing defeat for the Romulan Star Empire, and forced the Romulans into isolation for the next century.
Even into the 24th century, the battle remained an intense embarrassment for the Romulans. (TNG: "The Defector")
- It is unknown how this battle is connected with the planet Cheron, since that planet was unknown by the Federation until the 23rd century.