Four Years War

The Four Years' War was a conflict taking place between the United Federation of Planets and the Klingon Empire in the mid 23rd century.

The Battle of Axanar was one of the precipitating events of the war.

Star Trek: Avenger continuity
The Four Years' War takes place from 2255 to 2259. Among the noted commanders of the war were Captain Garth of the USS Constitution and Captain Robert Wesley of the USS Avenger.

Noted battles of this war include the Battle of Omicron Canaris.