A Starfleet admiral who secretly revived Khan to build weapons for a war with the Klingons, and was killed by him aboard the USS Vengeance.
Alexander Marcus is a high-ranking Starfleet admiral in the Kelvin timeline and the father of Carol Marcus. Expecting war with the Klingon Empire, he had Khan Noonien Singh revived from the Botany Bay and forced him to design weapons, including the warship USS Vengeance, under the false identity of John Harrison.
After Khan escapes, Marcus sends Kirk to fire torpedoes at him on Qo'noS, hoping to provoke war, and then tries to destroy the Enterprise with the Vengeance. Khan takes control of the ship and kills Marcus on its bridge. He was played by Peter Weller.