Karis Atum Tatenen was a 23rd century male native to the planet Khepri. By the late 2240s, Tatenen was serving as a command division officer in Starfleet, assigned to the USS King Richard as her commanding officer. He became famous across the Federation in 2248 after his brave deeds against several Klingon battleships during the Battle of Vonra, and was labelled as the "Destoyer of Klingons".
By the late 2270s, an elderly Tatenen had risen to the rank of fleet admiral and was one of the oldest officers in active service at that time. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
USS King RichardEdit
Around this time, the King Richard was near Pakheth, about three of four light-years from Tatenen's home star Ra, when she became involved in a skirmish with several Klingon scout ships. However, the King Richard's skirmish with the scout ships proved to only be a pre-cursor to a pitched battle with several Klingon battleships near Vonra. Although the King Richard was vastly outnumbered, Tatenen persevered in the battle and had kept on firing volley after volley at the Klingons.
After the King Richard had emerged victorious, completely devastated in the battle, Tatenen was labelled as the hero of the battle and was nicknamed the "Destroyer of Klingons". Following the battle, receptions were held in Tatenen's honor at Federation headquarters, he was invited to make a grand speech at Starfleet Academy and he even made an appearance before the Federation Grand Council. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
By the early 2250s, Tatenen had written his account of the battle and published it as Battle of Vonra. In the years following the battle, Tatenen continued to serve in Starfleet, and went on to fight many more battles against both the Klingons and the Romulans, eventually rising to the rank of fleet admiral. By the late 2270s, Tatenen was one of the oldest officers still serving in Starfleet, and at this point, was assigned to his homeworld on Khepri with his staff, including Captain Tapia, Baroness Commander Amalia, Commander Ogar and Lieutenant Commander Anderson.
In 2277, Starfleet Command ordered Tatenen to represent the Federation in diplomatic talks with Klingon Ambassador Kaare on the planet Pollox IV, in the hopes in bringing an end of hostility and ushering in a new era of peace between the two powers. Departing for Pollox aboard the USS Enterprise, under the command of Admiral James T. Kirk, Tatenen spent much of his time telling Kirk and his senior staff about how diplomacy was a lost art with the Klingons and that preemptive action was the best way of dealing with them.
Shortly after arriving in orbit of Pollox and detecting three Klingon Kl'ar-class vessels in orbit, Tatenen ordered Kirk to open fire on them before they had chance to react, even though Tatenen was at Pollox to discuss peace with the Klingons. Thankfully, Kirk refused to react and Tatenen eventually transported down to begin the talks. However, the talks soon broke down after Tatenen made a series of unreasonable demands on Kaare and the other representatives and Tatenen beamed back aboard the Enterprise and enacted Starfleet Order 1-202-B, which enabled him to commandeer any spacecraft for military purposes.
Realizing that Tatenen had sabotaged the talks, Kirk blanked the order and had a team of security guards lockdown Tatenen and his staff in the transporter room. Unfortunately, Tatenen managed to escape his captivity and was successfully able to steal the shuttlecraft Galileo and aim for a collision course with the Klingon vessels. Due to the Galileo's angle of departure, threading through the Enterprise's warp nacelles, the starship was unable to lock a tractor beam and stop Tatenen. Tatenen's ramming raid only ended when Captain Kang's vessel opened fire and destroyed the Galileo with a single phaser blast, killing Tatenen in the process. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
Although Tatenen was a fit and healthy man who had good health in his younger days, as he grew older his health started to fail and many of his vital organs began to fail. However, due to the "wonders of modern science", those organs could be replaced by artificial means. By the 2270s, Tatenen had had many organs, including his stomach replaced and joked that he "practically nothing that I was born with".
As well as the replaced organs, Tatenen also found himself dependent on a variety of different medications, which he relied on his aide-de-camp, Amalia, to help him administer. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")