The rotation you're describing is along the pitch axis. In layman's terms, it pitches around the middle (aka Centre of Gravity) where the wings are mounted. (Very basic description). It's the elevators (in a conventional aircraft) on the tail that initiates the action though. The axis is not a fixed point in an aircraft and it's influenced by where the mass is loaded (people/freight/luggage) and how much fuel is on board.
In this case, think of a line drawn straight across from wing tip to wing tip and the aircraft rotates around that, as in, nose comes up.
Transverse/lateral/pitch.
A simple
wiki description.