The Behemoth-class Battlecruiser is the strongest military spaceship of the Terran Fleets in the StarCraft Universe. According to known background, Terran Battlecruisers were invented and first built by the Terran Confederacy during the Guild War. These heavily armed and armored battleships ensured Confederate victory. When the Korhal uprising started, 20 Battlecruisers were sent to Korhal by the Confederate Government, to deal with the insurgency. In an act of genocide, the order was given to unleash thousands of Apocalypse-class thermonuclear missiles, killing the 4,000,000,000 or so people inhabiting the planet.
The Battlecruiser is used for two main purposes - battle with other starship(s) and bombarding the surface of planets. Theses ships are also capable of atmospheric flight for ground support.
In RTS StarCraft and StarCraft: Brood War Terran Battlecruiser is the strongest Terran unit. It is built in the StarPort building. Battlecruiser is armed with multiple heavy laser cannons and with the Yamato Gun, capable of destroying another battlecruiser in one shot.