The Yorktown-class was a type of United Earth battleship used by United Earth Starfleet during the 22nd century. It was originally commissioned as an early-model Human military vessel, proving to be one of the most powerful and largest vessels of it's time, at 400 meters in length. It's service continued into the early 23rd century, where it was enlisted by Starfleet as a Federation starship. (ST video game: Legacy)