The word saeculum derives from the same root as the Latin verb serere, “sow”; it suggests the notion of a group of human beings sown as seed: when the last seedling of a sowing has vanished, a saeculum has reached its end and a new saeculum begins. This background helps explain the rather vague definition of saeculum by Censorinus as “the longest possible human lifetime” (XVII 2), while Varro limits it concretely to 100 years (De lingua latina VI 11).
Following the Etruscans, who divided their history into ten saecula of varying length, Rome observed periodic interval…