Lustration (Lat, lustratio, also lustrum), purification by sacrifices or other ceremonies. Originally ablution in water was the only rite observed by the Greeks, but afterward sacrifices, etc, were added. They were employed both to purify individuals, cities, fields, armies, or states, and to call down the blessing of the gods. The most celebrated lustration of' Greece was that performed at Athens, in the days of Solon, by Epimenides of Crete, who purified that city from the defilement incurred by the Cylonian massacre. A general lustration of the whole Roman people took place every fifth year, before the censors went out of office. On that occasion the citizens assembled in the Campus Martius, and the sacrifices termed suovetaurilia, consisting of a sow, a sheep, and an ox, were offered up, after being carried thrice round the multitude. This ceremony, to which the name lustrum was particularly applied, is said to have been instituted by Servius Tullius in 566 B. C, and was celebrated for the last time at Rome in the reign of Vespasian. The term was also applied to the period which intervened between the lustra, and, as that period consisted of five years, later writers occasionally used the word lustrum to designate that space of time generally.

All Roman armies were lustrated before they commenced military operations. The Roman shepherd at the approach of night adorned his fold with branches and foliage, sprinkled his sheep with water, and offered incense and sacrifices to Pales, the tutelary divinity of shepherds. "Whatever was used at a lustration was immediately after the cere-mony cast into a river, or some place inaccessible to man, as it was deemed ominous for any one to tread on it.