Ekpe was already a mature, fully graded institution by the time the earliest outside observers described it, so their accounts date contact rather than founding, and Cross River oral tradition does not preserve a single founder or a securely countable founding year.
What would resolve this Comparative Ejagham and Efik oral-tradition fieldwork or an archaeological or documentary find independently datable to a period before the earliest colonial-era accounts, tying an early stage of Ekpe's grade structure to a place and an approximate century.
OpenWest African historical anthropology and oral tradition studiesIvor L. Miller, Voice of the Leopard: African Secret Societies and Cuba