A saeculum is a length of time roughly equal to the potential lifetime of a person or the equivalent of the complete renewal of a human population. The term was first used by the Etruscans. Originally it meant the period of time from the moment that something happened (for example the founding of a city) until the point in time that all people who had lived at the first moment had died. At that point a new saeculum would start. According to
legend, the gods had allotted a certain number of saecula to every people or civilization; the Etruscans themselves, for example, had been given ten saecula.
By the second century BC, Roman historians were using the saeculum to periodize their chronicles and track wars.At the time of the reign of emperor
Augustus, the Romans decided that a saeculum was 110 years. In 17 BCCaesar Augustus organised Ludi saeculares ('century-games') for the first time to celebrate the 'fifth saeculum of Rome'. Later emperors like Claudiusand Septimius Severushave celebrated the passing of saecula with games at irregular intervals. In 248, Philip the Arabcombined Ludi saeculares with the 1000th anniversary of the founding of Rome' ab urbe condita'. The new millenniumthat Rome entered was called the "Saeculum Novum",fact|date=January 2008 a term that got a metaphysical connotation in Christianity, referring to the worldy age (hence 'secular').fact|date=January 2008
A saeculum isn't normally used for a fixed amount of time, in common usage it stands for about 90
years. It can be divided into four "seasons" of approximately 22 years each; these seasons represent youth, rising adulthood, midlife, and old age.
Social cycle theory
Wikimedia Foundation. 2010.