Liturgy (Gr. neitovpyia, a public act or service), in general, the totality of the prayers and ceremonies which are used by a church for the celebration of divine worship. More commonly, however, it is taken in a narrower sense, and denotes those formularies or books which contain these prayers and ceremonies. Those who administered the liturgy were called in the ancient church neitovpyoi, a term which denoted in Athens the managers of public spectacles, but in later times came to be used exclusively in an ecclesiastical sense. Moses established days for public worship, various sacrificial rites, and forms of words to be used on specified occasions. This national order of public worship was made more pompous under Solomon, and afterward it became customary to accompany the offering of sacrifices with psalmody. In these forms Christ and his apostles joined. He also left one form of prayer which has been in universal use among Christians, and the rites of the Lord's supper and baptism, which have been all but universal.

I. Psalmodic Liturgies

It appears well established that the first Christians met at certain hours to pray and sing psalms. The Septuagint version of the Psalms was used for this purpose in the Greek churches, and the old Italic version in the Latin till St. Jerome, by order of Pope Damasus, corrected at first the Italic version, and afterward translated the psalms from the Hebrew and arranged them in a suitable order for the divine office. This psalter was introduced throughout the West. Pope Gelasius added hymns to it; and by degrees lessons from the Old and New Testaments, commentaries from the church fathers, and the acts of the local martyrologies relating to the saints commemorated on each day, became a part of the psalmodic office. Thus grew up the long liturgy of the East, and what in an abridged form became the breviary of the western churches. (See Breviary.) An important part of this office was the litany (Gr. nitaveia, supplication), which consisted at first in the deacon's reciting from the ambon the most important objects of supplication, to each of which the congregation responded " Lord, have mercy," "Christ, have mercy," "Hear us, Lord," "Help us, Lord," etc.

These successive appeals to the persons of the Trinity were known as the lesser litanies; but gradually, after the 4th century, these responsive forms were lengthened, became usual in solemn processions, and were then called the "greater litanies." The sacramental offices or liturgies were distinguished in the beginning by a few simple forms, still underlying the diversity and multiplicity of rites gradually superadded. The primitive forms relating to baptism and the Lord's supper especially have been preserved without alteration. They were carefully handed down unwritten from generation to generation till the age of Con-stantine, when sacramentaries or liturgical formularies were published, containing the whole order of divine service.

II. Eucharistic Liturgies

As in the sacramental system the eucharist or Lord's supper occupied a central position, the term liturgy began to be applied chiefly or exclusively to its celebration. The eastern eucharistic liturgies are usually classed into four groups: 1. The " liturgy of the apostles," sketched in the 8th book of the apostolic constitutions attributed to St. Clement, in general use during the first four centuries, and which served as a groundwork for subsequent rituals. 2. The liturgy of St. James the Elder, used in the patriarchal churches of Jerusalem, Antioch, and their dependencies. The Greek version of it was successively corrected and amplified by St. Basil the Great and St. John Chrysostom. This version was introduced into the church of Constantinople in the 6th century, and has ever since continued to be used there. It is the original of the Slavic liturgy of St. Cyril, which became the liturgy of the Russo-Greek church and its offshoots. The Syriac liturgy of St. James in use at Antioch is considered to be a free version. Modified to suit the Monophysite doctrines, it has been everywhere one of the favorite liturgical forms of the Jacobite churches.

Modified to suit the opposite Nestorian tenets, it has always been used by the Nestorian churches of Armenia, Mesopotamia, Persia, and the East Indies. 3. The Alexandrian liturgy, attributed to St. Mark, received its complete form from St. Cyril of Alexandria. He permitted it to be translated into Coptic and used by the Coptic churches throughout Egypt. It was also translated into the Ethiopic, and has always been used by the Abyssinian churches. The Mono-physites employ no fewer than 28 different liturgical forms, each named after some apostle or saint. 4. The liturgy of St. John the Apostle, or Ephesian liturgy, though superseded in the East by that of St. James after the 4th century, appears to have been introduced into southern Gaul by St. Irena3us and St. Pothinus, and to have served as the prototype of the early rituals of Gaul, Spain, Great Britain, and Ireland. - The Roman liturgy, ascribed by Catholics to St. Peter, was in use throughout Italy till after the age of Constan-tine. It was embodied in the sacramenta-ries of St. Leo the Great, St. Gelasius, and St. Gregory the Great. The most remarkable innovation of the Gregorian liturgy was the establishment of an ecclesiastical chant which helped toward the general adoption of the whole Gregorian liturgy by the western churches.

The Roman sacramentary received at an early date the name of missal or mass book, and contained at first only what the officiating bishop or priest recited or sang at the altar, namely, the canon with the prefaces and collects. To these were afterward added what was sung in the choir; and finally, in the 9th century, appeared the complete or "plenary missal,'1 containing, with the above additions, the lessons, epistles, and gospels, or what belonged to the office of lectors, subdeacons, and deacons. In this form the Roman liturgy continued to exist till the council of Trent appointed a commission to revise it. This revision was promulgated as the "Roman Missal " by Pius V. in 1570, and was further corrected by Clement VIII. and Urban VIII. The Milanese or Ambrosian liturgy was never superseded by the Gregorian, and was formally sanctioned as the "Ambrosian rite " by Alexander VI. - The Mozarabic and Gallican liturgies have already been alluded to as offshoots of the Ephesian liturgy of St. John. The former, supposed to have been named from its being adopted by the mixed population of Goths and Arabs in Spain (Mixti-Arabes), was introduced in the 6th century.

It began to be replaced by the Gregorian ritual in the 11th century, and in the 16th its use was limited to a single chapel in the cathedral of Toledo. In Gaul special sacramentaries were composed by St. Hilary of Poitiers (died about 368), by Musasus, a priest of Marseilles, and by Sido-nius Apollinaris, bishop of Clermont (died about 484). That of the church of Lyons, claiming St. Irenasus for its author, subsisted till quite recently, when it was superseded by the Roman missal and breviary. The rituals in use in the various dioceses of France before 1789 were the work of the respective bishops. The Roman court protested against their introduction. The last of them gave way in the diocese of Paris to the Roman liturgy in 1874. St. Augustin on his arrival in Britain found such liturgical diversity among the Saxons, that he was advised by St. Gregory the Great to allow the local churches to adopt either the Gallican or the Roman ritual, or such portions of them as best suited established customs.

The Norman bishops after the conquest made strenuous efforts to introduce uniformity.

Thence came the Salisbury liturgy, or "use of Sarum," which did not differ substantially from the Gregorian rite, and which became general in Ireland, and was adopted in many places on the continent. Many local customs or " uses " subsisted in England till the reformation.

III. Protestant Liturgies

A complete history of the liturgy of the church of England and of the Protestant Episcopal church of America is given under the title Common Prayer, Book of. Of the Protestant liturgies, the first in chronological order was Luther's Taufbuch-lein, published at Wittenberg in 1523, followed by Formula Missce et Communionis in 1524, a hymn book entitled Enchiridion, and his Deutsche Messe in 1526. Luther wished to introduce as few changes as possible; he made the Lord's supper the central part of his liturgy, gave a more prominent part to preaching, and retained the church music. Of the churches reformed through his instrumentality, some adhered to the Wittenberg order of service, while others adopted the simpler forms of Zwingli and Calvin. However, in northern, eastern, and middle Germany this Lutheran ritual has been always maintained. In the Scandinavian kingdoms and Iceland, the preservation of the episcopal office contributed to that of the old liturgy in its main features. Although no one form of public worship is obligatory among Lutherans, as in the church of England, the conservative portion of them were strongly attached to the old forms, while the progress of liberal and rationalistic ideas inclined the remainder to a ritual more adapted to their wants.

The Prussian government' published in 1822 the union liturgy, made obligatory both on Lutherans and Reformed in Prussia, and aiming at uniting them in one evangelical state church. This measure, as well as others subsequently taken in the same direction, led to a wide-spread resistance, which ended in the formation of the " Separated Lutheran" churches. These were granted a legal status in 1845, and are governed by a high consistory of their own, and preserve the old liturgy of their fathers. - The Moravian liturgy, preserved in the works of Bishop Amos Comenius, and published in 1632, served as a basis for the present ritual of the United Brethren, which was compiled by Count Zinzen-dorf from the Greek and Latin services. This liturgy comprises the orders for the Lord's supper, baptism, betrothal and marriage, confirmation, ordination, and burial. There are litanies for Sunday morning service, and a choral office with music. (See " Liturgy and Hymns for the Use of the Protestant Church of the United Brethren," London, 1849.) - The liturgy of Calvin differs much from that of Luther. There is no responsive portion, but there are offices for the Lord's supper, and for baptism and marriage.

The liturgy of Geneva is moulded on that of Calvin; and the churches of continental Europe in sympathy with the Calvinistic system have rituals closely resembling the Genevese. The church of Scotland received her order of divine worship from Knox, who drew it up at Frankfort, tried it at Geneva, and made it obligatory in Scotland in 1564. The "New Book of Scotland," published in 1(344, combined the main features of the liturgies of Calvin and Knox. The only guide for the Presbyterian order of worship is the Westminster " Directory for the Public Worship of God." Some Congregational and Baptist churches have adopted written forms for the administration of baptism and the Lord's supper, and for marriage and burial services. The Swedenborgians (New Jerusalem church) admit the Lord's prayer as the one fixed form, and with it they have a choral and responsive service, including the psalms of David recited or sung to old Gregorian music, and separate services for the sacraments and special occasions. Unitarianism, having no priestly order, nor indispensable, saving sacraments, has no established liturgy. In most Unitarian congregations there is a communion service, whose efficacy is believed to consist principally in fostering religious feeling.

The ordinary services are very simple, consisting of prayer, preaching, and singing; and an afternoon service is now adopted by some congregations, in which choral music is used with much effect. - See Muratori, Liturgia Romana Vetus (2 vols., Venice, 1748); Assemani, Codex Liturgicus Ecclesice Universalis (13 vols., Koine, 1749-'66); the Lutheran Daniel, Codex Liturgicus Ecclesice Universal (4 vols., Leipsic, 1847-'54); Mone, Lateinische und Griechische Messen aus dem, 2ten bis 6ten Jahrhundert (Frankfort, 1850); Neale, " The Liturgies of St. Mark, St. James, St. Clement, St. Chrysostom, and St. Basil" (fob, London, 1859); and "Liturgies and other Documents of the Ante-Nicene Period " (Edinburgh, 1872).