The city of Zamora was founded at the beginning of the Bronze Age, being later occupied during the Iron Age by the Celtic people of the vacceos, that denominated Ocalam. The initial settlement was in the almond delimited by the Castle and the San Ildefonso coast, a strategic location as it is a rocky plateau defended by the river Duero, in which a castro was located.
The settlement remained during the Roman Empire. In fact, he has often been identified with the important mansio and civitas of “Ocelo Durii” (Ojo del Duero). According to some such population would correspond in fact with the present Villalazán, twelve kilometers to the east, also on the banks of the Duero, and by which the Way of the Silver passed.