Litany, in Christian worship and some forms of Judaic worship, is a form of prayer used in services and processions, and consisting of a number of petitions. The word comes through Latin from Ancient Greek (litaneía), which in turn comes from (litê), meaning "supplication".
For the "Litany" as used in the Eastern Orthodox and Eastern Catholic Churches, see Ektenia.
The frequent repetition of the Kyrie was probably the original form of the Litany, and was in use in Asia and in Rome at a very early date. The Council of Vaison in 529 passed the decree: "Let that beautiful custom of all the provinces of the East and of Italy be kept up, viz., that of singing with great effect and compunction the 'Kyrie Eleison' at Mass, Matins, and Vespers, because so sweet and pleasing a chant, even though continued day and night without interruption, could never produce disgust or weariness".
The number of repetitions depended upon the celebrant. This litany is prescribed in the Roman breviary at the "Preces Feriales" and in the Monastic Breviary for every "Hora" (Rule of St. Benedict, ix, 17). The continuous repetition of the "Kyrie" is used to-day at the consecration of a church, while the relics to be placed in the altar are carried in procession around the church. Because the "Kyrie" and other petitions were said once or oftener, litanies were called planæ, ternæ, quinæ, septenæ.
Public Christian devotions became common by the fifth century and processions were frequently held, with preference for days which the pagans had held sacred. These processions were called litanies, and in them pictures and other religious emblems were carried. In Rome, pope and people would go in procession each day, especially in Lent, to a different church, to celebrate the Sacred Mysteries. Thus originated the Roman "Stations", and what was called the "Litania Maior", "Major Rogation" or "Romana". It was held on 25 April, on which day the heathens had celebrated the festival of Robigalia, the principal feature of which was a procession.