Lustrum

A Lustrum (Latin to lustrare " make bright ", " clean " ) was originally a purification or atonement, by which the carried out by the censors tax assessment and screening of citizens ( Census ) was completed in Roman religion. It took place on the Champ de Mars in front of the gates of Rome. One of the censors had three sacrificial animals ( suovetaurilia: boar, ram and bull ) lead to the assembled people around, which were then sacrificed to Mars.

Since the Lustrum repeated every five years, was the name from the late 3rd century BC, generally for a period of five years, a five-year period, in use. The word was popular with Roman poets from metrical reasons and has been preserved in the elevated language to this day.

Another historical name for a five-year period without reference to religion was the quinquennium.