The Battle of Vonra was a small-scale battle between the forces of the United Federation of Planets and the Klingon Empire in 2248, and was part of the ongoing Federation-Klingon Cold War. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
By the late 2240s, numerous star systems along the Federation-Klingon border were considered to be disputed territory by both powers, but a tenuous treaty prevented either side for making a grab for the disputed zones. However, this changed in 2248, and a number of Klingon warships, including scout ships and battleships, crossed the Klingon Neutral Zone and entered Federation space in contravention of the treaty.
Several Klingon scout ships were operating in the vicinity of Pakheth, around three light-years from Regulus, when they were discovered by the Federation starship USS King Richard, under the command of Karis Tatenen. The King Richard was able to quickly dispatch the scout ships and continue on with its previous mission. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
A short time after the encounter at Pakheth, the King Richard encountered several Klingon battleships operating near Vonra. Despite being heavily outnumbered and out-gunned, Tatenen and his crew persevered in fighting off the invaders, firing volley after volley until the starship was able to overcome the battleships. Despite the victory, the King Richard suffered extensive damage and was on the brink of suffering a warp core breach. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
Following the battle, Tatenen became revered across the Federation and was given the nicknames "Hero of the Battle of Vonra" and "Destroyer of Klingons". Even in the Klingon Empire, Tatenen became known as a brilliant strategist and tactician. Unfortunately, Tatenen's reputation became tarnished twenty-nine-years later, when he was chosen to represent the Federation in ground-breaking diplomatic talks with Ambassador Kaare of the Empire on planet Pollox IV. By this stage in his life, Tatenen had become very bigoted and believed that a pre-emptive strike was the best way of dealing with the Empire.
After sabotaging the talks, Tatenen attempted to use the USS Enterprise to start an armed conflict with the Empire. When this failed, Tatenen stole a shuttlecraft and attempted to ram three Klingon vessels, but he was killed when the shuttle was shot down. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")