Kelvan War

The Kelvan War was a conflict between the Kelvans and the combined forces of the, the Klingon Empire and the Romulan Star Empire in 2285.

While most of the Gorn species was killed during the invasion, the Kelvan forces were defeated by the combined assets of the three indigenous governments. {Orion Press: In Harm's Way)

Reference

 * Roberts, d. William. In Harm's Way. (Orion Press)