Maximilian Forrest was the commanding officer of the ISS Enterprise.
In 2155, while en route to link up with the rest of the Terran fleet, the Enterprise's first officer, Commander Jonathan Archer betrayed his captain and took command for himself, throwing Forrest in the brig. Forrest broke free with the help of T'Pol, retook the ship and placed Archer in the agony booth. Upon retaking the bridge, Forrest and his troops discovered that Archer had locked the navigational controls on a set course and it could not be changed until the ship had reached its destination.
After Archer's release from the booth, Forrest informed him that the Admiral was intrigued by Archer's information and that he had an hour until he briefed the senior staff. At the officer's briefing, Archer revealed that he had learned that the Tholians had obtained a starship not only from a mirror universe, but also from one hundred years in the future. Archer argued that the technology of this future ship could be used by the Empire to help crush the rebellion. This argument did not impress Captain Forrest, but he was still unable to override the controls, and since Archer's mission was sanctioned by Starfleet Command, Forrest reluctantly carried out the mission. However, he made it clear to Archer that his act of betrayal would not be forgiven or forgotten. In fact, the scorned captain saw his chance for revenge much sooner than he had first thought. He approached his Vulcan ally before she transported over to the future ship and instructed Commander T'Pol to make sure Archer did not make it back. While Archer's landing party was on the USS Defiant, The Tholians attacked the Enterprise. The fight did not go well and the Enterprise was destroyed, taking Captain Forrest with it. (ENT: "In a Mirror, Darkly")