He was known among his fellow officers as a brilliant tactician as well as a superb mentor to junior officers. Many commanding officers fought over his former crew members.
In 2333, against his father's wishes, Tachion entered Starfleet Academy. Within twenty minutes of setting foot on the grounds, he broke the jaw of a Vulcan 3rd Year Cadet, claiming that she had made a speciest slur about his heritage. It was the first of many fights he would get into over the subject.
Along with Cadets Shivvar th'Zaavreth, Spovik, Emtred Macik and Deisha Sillngford he was part of Omicron Squad.
He was originally a Science Cadet specializing in geology, but in his second year, he switched to Security. He had specialized training in using shipboard weapons to support planetary combat operations, as well as ground-based heavy weapons, including the photon mortar.
In 2340, during a patrol of the Federation-Cardassian border, the Gettysburg was severely damaged during a battle with a pair of Cardassian frigates. Phasers were offline, but Tachion managed to channel battery power from an escape pod for two phaser blasts, enough to drive the Cardassian vessels off.
After the Romulan attack on Khitomer, he headed a classified Starfleet mission: a strike on a Romulan target, made to look like a Klingon reprisal. This attack took out several sensor girds, allowing Starfleet Intelligence to insert several unmanned probes deep into Romulan space for the first time in decades.
He was promoted to Lieutenant Commander in 2349.
In 2351 he transferred to the USS Ambassador as Chief of Security and Second Officer prior to vessel resupplying the Federation colony on Dorvan V. When the ship moved on to the next colony, he and Ensign Chakotay stayed behind with a shuttle to upgrade the planet's defense grid.
During the Tzenkethi War, while leading a team to secure a hospital against an oncoming Tzenkethi armada, he was forced to lead his team and a large group of patients that hadn't been evacuated into a bar a few blocks away. They holed up for five days, defending it against enemy ground forces. Unknown to him at the time, his actions kept the force he was engaging from pursuing fleeing civilians. He was awarded the Starfleet Citation for Conspicuous Gallantry and promoted to Commander for his actions.
He attended the commissioning of the USS Cheyenne while there.
In 2361 he assumed command of the USS Vigilant.
He recruited several comrades for his senior staff, including Roger Deict and Renee Boyce.
The ship was destroyed in 2364 in a battle with eight Cardassian vessels. Tachion underwent a very public and brutal trial for the loss of the ship, but was cleared in the end and awarded the Grankite Order of Tactics with the Class of Excellence and offered command of USS Drake.
He turned down the command, instead becoming a Strategic Operations Officer at Starfleet Command on Earth, a position which had him reacting to different trouble spots across the Federation.
In early 2365 he embarked on a classified mission aboard the USS Constantine.
Later that year he turned downed command of the USS Aries.
When the armada met the Borg Cube at Wolf 359, Tachion was on temporary duty as Strategic Operations Officer aboard the USS Endeavour, the only ship to survive the battle in any spaceworthy condition. After the death of the XO and Captain Amasov being taken to sickbay, he allowed the ship's second officer, Lieutenant Commander Kiva, to assume command even though he was higher ranking. Instead, he manned Tactical as the USS Endeavour limped out of the battle.
In testimony after the battle, he said he disagreed with the decision to flee and that regrouping with the arriving USS Enterprise-D and other reinforcements would have been a better decision. Kiva felt that this testimony kept him from an XO slot, and the two did not speak again until 2371.
Defiant Class ASDBEdit
In the aftermath of Wolf 359, several officers who had survived the battle were called together to design a new type of heavy escort at Utopia Planitia, the Defiant class, under Admiral Batelle Toh. Tachion submitted a design for a high-speed torpedo vessel, but a more compact design was ultimately chosen. However, against his wishes, the design was eventually used for the Nova class.
In 2368, he was head of a special team of instructors tasked with retraining the officers from the USS Bozeman that chose to continue serving in Starfleet. He was also instrumental in recruiting engineering cadets to aid in the ship's refit. Afterward, he was assumed command of one of the Academy's training vessels, the USS Republic.
In 2369 Tachion was promoted to Captain and temporarily assumed command of the USS Cairo while Captain Edward Jellico transferred to the USS Enterprise-D. He stood off three Cardassian light cruisers in the Saltok System. During his time in the ship's center seat, he first met Seff O'Rourke, who would end up serving under him aboard the Lionheart and on several missions during the Dominion War.
When Jellico returned to the Cairo Tachion resumed his teaching post at the Academy.
In late 2370, the Dominion threat drove to the reactivation of the Defiant Project. Six ships were ordered constructed immediately and Tachion was given command of the third spaceframe, being constructed at the New London Fleet Yards. ("New Orders")
In mid-2373, after Deict was arrested for treason, Tachion was informed that he was being transferred immediately to the USS Brazen as Commanding Officer. He and his belongings were moved by site to site transport, and the Brazen left the starbase within forty-five minutes of his arrival.
The Brazen, along with most of the Seventh Fleet, was lost at the Battle of Tyra in early 2374. Tachion and eight others managed to survive by ejecting the bridge module. They were taken prisoner by Dominion forces.
They ended up at a Dominion Prisoner of War Camp, along with others from previous battles.
After his rescue, he and Seff O'Rourke took part in several missions for Starfleet Special Operations.
By stardate 51893.2 he was back in the center seat of the Lionheart, which served as Commodore Nikolas Stone's flagship during the Third Battle of Vulcanis.
Upon the return of the Sixth Fleet's task force to Prophet's Landing, he was placed in command of the USS Camelot, which would serve as Stone's flagship for the rest of the war.
His mother was Relivi a Romulan exile who was smuggled out of the Empire by Starfleet Intelligence in return for her father, Centurion Sutrev turning over the remains of a cloaked and hidden Romulan Star Navy Frigate.
Starting during his Freshman year at Starfleet Academy he was involved on and off again with fellow cadet Patricia Rivers, who would later command the USS Hargrave, with which she would transport him to take command of the Lionheart in 2371.
In 2363 he married Lieutenant Commander Miranda Garrett, older sister of his former USS Ambassador shipmate and friend Ronald Garrett. They lived in a condo in the California city of Half Moon Bay, 25 miles south of San Francisco. While he was at Starfleet Command she was part of the construction crew of the Nebula class USS Melbourne. Unfortunately, she was aboard the ship when it was destroyed at the Battle of Wolf 359, serving as Captain Thomas Halloway's XO when it was hastily launched from Utopia Planitia to confront the cube.
Tachion and Sisko were introduced by Ambassador Curzon Dax during the memorial ceremony for those killed by the Borg in 2367. Later, while designing the Defiant class the two widowed officers found comfort in each others company, which then extended to a friendly rivalry to earn command of the prototype vessel. The friendship would be renewed in 2371 when they worked together to get the USS Defiant spaceworthy to prove to Starfleet Command the class should be put into production.
While awaiting the USS Ambassador to pick him up at Starbase 76, Tachion met then Lieutenant Ronald Garret, the ship's Navigation Officer, returning from leave on Earth. The two spent their downtime playing poker. Eventually, Tachion married Garret's older sister Miranda, and in 2371 recruited his son, Lieutenant Junior Grade Michael Garrett, as Navigation Officer of the USS Lionheart.
Then Lieutenant Riley was Chief Engineer of the USS Ambassador when Tachion came aboard, and close friends with Ronald Garrett. However, since Garrett was married, Riley and Tachion often excluded him from some their shore leave activities.In 2371 Riley, now a Captain, was CO of Starbase 315 and the New London Fleet Yards where the USS Lionheart was being constructed. Still a bachelor, he welcomed his friend for the duration of the construction project.
He first met the young engineer while aboard the USS Intrepid immediately following the Khitomer Massacre, and again on the USS Ambassador. Deict was part of the team Tachion was stranded with on Amoz III and defended a bar against the Tzenkethi invaders.
Tachion brought him aboard the USS Vigilant as Chief Engineer, and again when he assumed command of the USS Lionheart. On both vessels, he was one of the few things Tachion could always rely upon.
She was a physician at the hospital on Amoz III and stayed with the patients that couldn't be evacuated at the bar. During the five day standoff, she was so impressed with the Starfleet crew's actions she applied to Starfleet Officer Candidate School. When Tachion assumed command of the USS Vigilant, he brought her aboard as Chief Medical Officer, and again aboard the USS Lionheart.
After the betrayal by his Operations Officer during the Maquis hijacking of the Lionheart in 2371, Stone was her replacement. Taking note of the Human/Vulcan hybrid's quick thinking and grasp of tactics he mentored the officer and made him his XO in late 2372. Stone would succeed him as the Lionheart's CO in 2373.
When the young pilot came aboard as his murdered godson's replacement, he wanted to hate him, but instead, the Kelt ended up as a surrogate son alongside Nikolas Stone.
The pair would end up feuding over Roger Deict's death in 2372, but come to terms while in a Dominion POW Camp. They would later perform several special operations together during the war.