pro·to·his·to·ry 
(prō′tō-hĭstə-rē, -hĭstrē)
(prō′tō-hĭstə-rē, -hĭstrē)n.
The study of a culture just before the time of its earliest recorded history.
pro′to·his·tori·an (-hĭ-stôrē-ən, -stŏr-) n.
pro′to·his·toric (-hĭ-stôrĭk, -stŏr-) adj.