Romulus founded Rome, he supposedly saw a flock of twelve vultures, which he took to be a signal that Rome would last twelve units of time. Eventually, the early Romans (who turned to Etruscan learning on such matters) came to assume that the twelve vultures must refer to twelve saecula. This assumption was confirmed by a set of prophetic books presented by an old sibyl to Tarquin the Proud, the last king of Rome and himself an Etruscan.
