Kyrie, is a common name of an important prayer of Christian liturgy, also called the Kyrie eleison (Greek: Κύριε, ἐλέησον, Kýrie eléison, "Lord, have mercy"). 4th century nun Egeria notes that worshipers employed the acclamation during the lamp-lighting ceremony of vespers in Jerusalem. In Orthodox services is a response to litanies; in Catholic churches, it is a responsitorial part of the Mass.