Scott Shepherd was a high ranking member of Starfleet.
He was born to K'nok, a Klingon, and Vareana, a Vulcan, on the year 2238. He was born in Starfleet Medical, and was one of the first ever Klingon-Vulcan Hybrids. He went to study at Starfleet Academy when he was 18 and served on his first ship, the USS Challenger when he was 21. He was promoted from enlisted to lieutenant junior in 2267.
Service Aboard the Monitor
After his service aboard the Challenger he went to service aboard the USS Monitor in 2268, where a year later he was promoted to Lieutenant during his service aboard this ship. In 2270, the Monitor was destroyed by a supernova, but luckily Shepherd and 16 other crew members were on an away mission at the time, and survived the ships demise. During that year, Shepherd's Aunt and Uncle died when their cargo vessel was boarded by Orion pirates, lucky his niece was bale to survive the attack and was rescued by Starfleet. With no one left in his family, as his mother died in the same attack, and his father left before he was born, he was forced to look after the little Ann'Belle. But he then rejoined Starfleet in 2275 where he and his niece, who just finished in the Academy, left to serve on the same ship.
Service Aboard the Rutherford
He went on to serve on the USS Rutherford with his niece that same year. He served as Chief nurse and one of the top researchers. He joined the crew on a long range exploration mission for 13 years, where he got involved in many skirmishes with the Klingons. During the last 3 years of the ships mission, Scott Shepherd was promoted to a full Commander, and after 2289, he went back to Earth for reassignment. His niece continued to serve aboard the ship even after his depart. The ship was decommissioned 12 years later, resulting in Shepherd's niece to teach at Starfleet Academy.
Service Aboard the Republic
His promotion would lead to him serving on the USS Republic in 2291, as the ship's first Officer. But when the ship was attacked by Romulans, the Captain of the Republic dies, forcing Scott to take command, which Starfleet later accepts and promotes the Commander to Captain.
After serving on the Republic for several more years and serving on other vessels later on, he finally captains the USS Danton in 2370, and leads it into the Dominion War several years later, where it is eventually destroyed in 2375, but again Scott is lucky to survive when he is beamed out of his ship with more of his crew, by the USS Defiant, before the Danton is destroyed by the Dominion fleet at Cardassia.
Service Aboard the Valkyrie
He then serves aboard the USS Valkyrie in 2376, where it fights in the second dominion war and explores the vast unknown that is the Gamma Quadrant. It is then decommissioned in 2389, just before Captain Shepherd is promoted to Admiral.
He then goes on to serve on board the 25th century refit of Enterprise, renamed the USS Vortex. The ship is captured by the Borg on its first mission, where he is assimilated, but because of his unique physiology, the Borg nanites are resisted by his body and Shepherd is able to save himself and his crew and escape on a captured Borg sphere, where he returns to the Alpha Quadrant and tests the First Pegasus-class ship, based on the technology reverse engineered from the captured sphere.
He lives to the year of 2434 at the age of 196, where he dies via a disease caused by his exposure to the Borg nanites, and the process his body went through to resist them. Starfleet medical predicted that if Admiral Shepherd had not caught the cellular degenerative disease, he could have possibly lived an extra 70-90 years. His niece runs his funeral ceremony, that is a mixed Vulcan and Klingon service. Many famous people came to his funeral, including, Admiral Worf. A statue was built of him in 2436, with it was the model of every ship he served on, floating around him.