In English, since around 1600, the word palladium has been used figuratively to mean anything believed to provide protection or safety, and in particular in Christian contexts a sacred relic or icon believed to have a protective role in military contexts for a whole city, people or nation. Such beliefs first become prominent in the Eastern church in the period after the reign of the Byzantine Emperor Justinian I, and later spread to the Western church. Palladia were carried in procession around the walls of besieged cities and sometimes carried into battle.