Battle of Cheron
The Battle of Cheron was a pivotal battle that took place in 2160, between the Romulan Star Empire and an Earth/Andorian/Vulcan/Tellarite alliance. The outcome of the battle effectively ended the Earth-Romulan War, with the "humiliating defeat" of the Romulans. ( production art) The United Federation of Planets was founded shortly after this conflict, in 2161. ()

Even into the mid-24th century, the battle remained an intense embarrassment for the Romulans, which, according to Alidar Jarok, would be avenged by "the new leaders" on Romulus, who "vowed to discard the treaty and claim the Neutral Zone," with Nelvana III being the first step. ()

Appendices

Background information
After the Battle of Cheron had first been mentioned in "The Defector" in 1990, it was not until 2005 that a computer screen seen in "In a Mirror, Darkly, Part II" presented the first canon reference to when and in which context it took place. The same computer screen, which displayed a historical archive entry mentioning a "Human/Vulcan/Andorian/Tellarite alliance" winning the Battle of Cheron in 2160, is also the only canon reference that these races fought the Romulans alongside Earth forces.

An article in the Picard family album that wasn't seen on screen was titled "Foe in retreat after Cheron debacle" in reference to this battle.

According to the reference book Star Trek: Federation - The First 150 Years, the planet Cheron seen in  was the namesake of the battle.

However, according to Star Trek: Star Charts (pp. 60 and 67) and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"; "The Romulan War: An Astrographic Brief"; "Portion of the Romulan Star Empire"), the Battle of Cheron was fought in the Cheron () star system. The primary was a F-class star and was located in the Romulan War Theater of Operations (2156-2160). The Battle of Cheron was fought in this system on January 10, 2160. According to a map of the Romulan Star Empire – prepared by the Stellar Archive Artist Lsel Essik, from the Romulan Master Data Catalog, in 2366 – Cheron was identified as a Romulan system. (The homeworld of the Cheron natives was located in the Cheron () system.

The battle was described in the  novel To Brave the Storm as a battle at the planet Cheron seen in "Let That Be Your Last Battlefield".

External link 
 

bg:Битка при Херон
de:Schlacht von Cheron
es:Batalla de Cheron
nl:Slag om Cheron
Conflicts
Earth conflicts
Deleted and unused material in background