James T. Kirk had his first deep space assignment under Garrovick, who was one of the finest men Kirk had ever known. During a mission to Tycho IV in 2257, Garrovick and two hundred of his crew were killed by a dikironium cloud creature.
Kirk felt terrible guilt over his captain's death; it was not until many years later that Kirk learned that there was very little he could have done to prevent the disaster, as phaser fire had no effect upon the creature. (TOS: "Obsession")
Star Trek: The Original Series - Core Game Book calls him Thomas Garrovick.
His mirror universe counterpart was mentioned in the short story "The Greater Good" contained in the anthology Shards and Shadows. In 2264, he was the captain of the ISS Farragut and took great pleasure in humiliating Lieutenant James T. Kirk in front of the entire crew. In revenge, Kirk arranged for Garrovick and two hundred of his crew to be killed by a dikironium cloud creature. He later claimed that he slept sounder the night after Garrovick's death than he had in years.
The Star Trek Into Darkness iTunes app likewise gives his first name as Stephen.
Star Trek New Voyages episode "In Harm's Way" also gives the name Stephen, as spoken by Captain Pike to Captain Kirk when disputing that Kirk was captain of Farragut.