It is all the clothing used by the clergy during the Divine Liturgy and other services as well as during ecclesiastical ceremonies, while functioning as insignia of ecclesiastical hierarchy and authority. In Orthodox worship the widespread use of functional attire and vestments already started from the first centuries of the Byzantine era. At that time, the need for separation from the rest of society, imposed special clothing on orthodox priests. The contemporary vestments of the clergy therefore essentially continue to maintain the Byzantine tradition, with particular sets of vestments for each of the individual orders of Priesthood, namely deacons, priests and bishops.