Compline (// KOM-plin; also Complin, Night Prayer, Prayers at the End of the Day) is the final church service (or office) of the day in the Christian tradition of canonical hours. The English word Compline is derived from the Latin completorium, as Compline is the completion of the working day. The word was first used in this sense about the beginning of the 6th century by St. Benedict in his Rule (Regula Benedicti; hereafter, RB), in Chapters 16, 17, 18, and 42, and he even uses the verb complere to signify Compline: "Omnes ergo in unum positi compleant" ("All having assembled in one place, let them say Compline"); "et exuentes a completorio" ("and, after going out from Compline...") (RB, Chap. 42).
Catholic, Eastern Orthodox, Anglican, Lutheran, and certain other Christian denominations with liturgical traditions prescribe Compline services. Compline tends to be a contemplative Office that emphasizes spiritual peace. In many monasteries it is the custom to begin the "Great Silence" after Compline, during which the whole community, including guests, observes silence throughout the night until the morning service the next day.
- This section incorporates information from the Catholic Encyclopedia of 1917. References to psalms follow the numbering system of the Septuagint, as said in the Latin of the Vulgate.
The origin of Compline has given rise to considerable discussion among liturgists. In the past, general opinion (including Bäumer and Batiffol) ascribed the origin of this Hour to St. Benedict, in the beginning of the 6th century. But Jules Pargoire and, later still, A. Vandepitte oppose this opinion and seek a more ancient origin for this Hour.
A text in Callinicus (between 447 and 450), first introduced in Father Pargoire's argument, informs us that between Vespers and the Night Office there was celebrated in the East a canonical Hour called in this text prothypnia, because it preceded the first sleep, being nothing other than what the Greeks today call apodeipnon, on account of the meal it follows (see Compline in Byzantine usage, below). However, in the thirty-seventh question of his Great Asketikon (Long Rules), St. Basil the Great, also, speaks of an intermediate Hour between Vespers and the nightly Office. Father Pargoire therefore disputes the assertion that St. Benedict was the originator of Compline, being rather disposed to trace its source to St. Basil.
In the article mentioned above, Father Vandepitte confirms these conclusions; nevertheless he states, in the clearest terms, that it was not in Cæsarea in 375, but in his retreat in Pontus (358-362), that Basil established Compline, which Hour did not exist prior to his time, that is, until shortly after the middle of the 4th century. Dom Plaine also traced the source of Compline back to the 4th century, finding mention of it in a passage in Eusebius and in another in St. Ambrose, and also in John Cassian. These passages have been critically examined, and Fathers Pargoire and Vandepitte have proved that before St. Basil's time the custom of reciting Compline was unknown.
At any rate, even if these texts do not express all that Dom Plaine says they do, at least they bear witness to the private custom of saying a prayer before retiring to rest. If this was not the canonical Hour of Compline, it was certainly a preliminary step towards it.
The same writers reject the opinion of Paulin Ladeuze and Dom Besse, both of whom believe that Compline had a place in the Rule of St. Pachomius, which would mean that it originated still earlier in the 4th century.
It might be possible to reconcile these different sentiments by stating that, if it be an established fact that St. Basil instituted and organized the Hour of Compline for the East, as St. Benedict did for the West, there existed as early as the days of St. Cyprian and Clement of Alexandria the custom of reciting a prayer before sleep, in which practice we find the most remote origin of our Compline.
Compline in the Roman Rite
It is generally thought that the Benedictine form of Compline is the earliest western order, although some scholars, such as Dom Plaine, have maintained that the Hour of Compline as found in the Roman Breviary at his time, antedated the Benedictine Office. These debates apart, Benedict's arrangement probably invested the Hour of Compline with the liturgical character and arrangement which were preserved in the Benedictine Order, and largely adopted by the Roman Church. The original form of the Benedictine Office, lacking even an antiphon for the psalms, is much simpler than its Roman counterpart, resembling more closely the Minor Hours of the day.
Saint Benedict first gave the Office the basic structure by which it has come to be celebrated in the West: three psalms (4, 90, and 133) as noted above said without antiphons, the hymn, the lesson, the versicle Kyrie eleison, the benediction, and the dismissal (RB, Chaps. 17 and 18).
The Roman Office of Compline came to be richer and more complex. To the simple Benedictine psalmody—modified, there is a fourth psalm, "In te Domine speravi" (Psalm 30)— and perhaps at a fairly late date it added the solemn introduction of a benediction with a reading (based perhaps on the spiritual reading which, in the Rule of St. Benedict, precedes Compline; RB, Chap. 42), and the confession and absolution of faults. This is absent from parallel forms, such as that of Sarum.
The distinctive character and greater solemnity of the Roman form of Compline comes from the response, In manus tuas, Domine ("Into Thy hands, O Lord ..."), with the evangelical canticle, Nunc Dimittis, and its anthem, which is particularly characteristic.
The Hour of Compline, such as it appeared in the Roman Breviary prior to the Second Vatican Council, may be divided into several parts, viz. the beginning or introduction, the psalmody, with its usual accompaniment of antiphons, the hymn, the capitulum, the response, the evangelical canticle, the prayer, and the benediction.
By way of liturgical variety, the service of initium noctis may also be studied in the Celtic Liturgy, such as it is read in the Antiphonary of Bangor, its plan being set forth by Warren and by Bishop (see Bibliography, below).
In the breviary of 1974 Roman Catholic Liturgy of the Hours, Compline is divided as follows: introduction, an optional examination of conscience or penitential rite, a hymn, psalmody with accompanying antiphons, scriptural reading, the responsory, the Canticle of Simeon, concluding prayer, and benediction. The final antiphon to the Blessed Virgin Mary (Salve Regina, etc.) is an essential part of the Office. Summorum Pontificum does allow Compline to be recited according to the older form.
Compline in Byzantine usage
Compline in the Eastern Orthodox and Greek-Catholic Churches (Greek (τὸ) Ἀπόδειπνον /apóðipnon/, Slavonic Povecheriye: literally the "after-supper" [prayer]) takes two distinct forms: Small Compline and Great Compline. The two versions are quite different in length.
At Compline (whether Small or Great), a Canon to the Theotokos in the Tone of the Week will normally be read (these Canons will be found in the Octoechos). Services to saints in the Menaion that, for one reason or another, cannot be celebrated on the day assigned to them, may be chanted on the nearest convenient day at Compline. In such cases, the Canon for the Saint would be read together with the Canon to the Theotokos, followed by the Stichera to the saint from Vespers. There are also particular days (such as certain Forefeasts, Afterfeasts, and days during the Pentecostarion) that have special Canons for Compline composed for them.
The Office always ends with a mutual asking of forgiveness. In some traditions, most notably among the Russians, Evening Prayers (i.e., Prayers Before Sleep) will be read near the end of Compline. It is an ancient custom, practiced on the Holy Mountain and in other monasteries, for everyone present at the end of Compline to venerate the Relics and Icons in the church, and receive the priest's blessing.
Small Compline is served on most nights of the year (i.e., those nights on which Great Compline is not served). On the eves of Sundays and feasts with All-Night Vigil, Compline may be either read privately or suppressed altogether. Among the Greeks, who do not normally hold an All-Night Vigil on Saturday evenings, Compline is said as normal.
The service is composed of three Psalms (50, 69, 142), the Small Doxology, the Nicene Creed, the Canon followed by Axion Estin, the Trisagion, Troparia for the day, Kyrie eleison (40 times), the Prayer of the Hours, the Supplicatory Prayer of Paul the Monk, and the Prayer to Jesus Christ of Antiochus the Monk. Then the mutual forgiveness and final blessing by the Priest. After this, there is a Litany and the veneration of Icons and Relics.
Great Compline is a penitential office which is served on the following occasions:
- Tuesday and Thursday nights of Cheesefare Week (the week before Great Lent)
- Monday through Thursday nights of Great Lent 
- Friday nights of Great Lent 
- Monday and Tuesday of Holy Week
- Monday through Friday during the lesser Lenten seasons: Nativity Fast, Apostles' Fast and Dormition Fast 
- The Eves of certain Great Feasts, as a part of the All-Night Vigil:
Unlike Small Compline, Great Compline has portions of the service which are chanted by the Choir  and during Lent the Prayer of St. Ephraim is said with prostrations. During the First Week of Great Lent, the Great Canon of Saint Andrew of Crete is divided into four portions and read on Monday through Thursday nights.
Due to the penitential nature of Great Compline, it is not uncommon for the priest to hear Confession during the service.
Great Compline is composed of three sections, each beginning with the call to prayer, "O come, let us worship...":
- Psalms 4, 6, and 12; Glory..., etc.; Psalms 24, 30, 90; then the hymn "God is With Us" and troparia, the Creed, the hymn "O Most holy Lady Theotokos", the Trisagion and Troparia of the Day, Kyrie eleison (40 times), "More honorable than the cherubim..." and the Prayer of St. Basil the Great.
- Psalms 50, 101, and the Prayer of Manasses; the Trisagion, and Troparia of Repentance, Kyrie eleison (40 times), "More honorable than the cherubim..." and the Prayer of St. Mardarius.
- Psalms 69, 142, and the Small Doxology; then the Canon followed by Axion Estin, the Trisagion, the hymn "O Lord of Hosts, be with us...", Kyrie eleison (40 times), the Prayer of the Hours, "More honorable than the cherubim....", the Prayer of St. Ephraim, Trisagion, the Supplicatory Prayer of Paul the Monk, and the Prayer to Jesus Christ of Antiochus the Monk. Then the mutual forgiveness. Instead of the normal final blessing by the Priest, all prostrate themselves while the priest reads a special prayer intercessory prayer. Then the Litany and the veneration of Icons and Relics.
In the Anglican tradition, Compline was originally merged with Vespers to form Evening Prayer in the Book of Common Prayer. ECUSA's Book of Offices of 1914, the Church of England's proposed Prayer Book of 1928, and the Anglican Church of Canada's Prayer Book of 1959 restored a form of Compline to Anglican worship. Several contemporary liturgical texts, including the American 1979 Book of Common Prayer, the Anglican Church of Canada's Book of Alternative Services, and the Church of England's Common Worship, provide modern forms of the service. The Common Worship service consists of the opening sentences, the confession of sins, the psalms and other Bible lessons, the canticle of Simeon, and prayers, including a benediction. There are authorised alternatives for the days of the week and the seasons of the Christian year. As a public service of worship, like Morning Prayer and Evening Prayer, Compline may be led by a layperson.
Among Lutherans, Compline has re-emerged as an alternative to Vespers. The Office of Compline is included in the various Lutheran books of worship and prayer books [along with Matins/Morning Prayer and Vespers/Evening Prayer]. Quite similar to Anglican use, in some Lutheran Churches Compline may be conducted by a layperson.
- The Catholic Enclopedia says: "It would be difficult to understand why St. Benedict, whose liturgical taste favoured solemnity in the Office, would have sacrificed these elements—especially the evangelical canticle—if, as Dom Plaine theorizes, his form of the Office were a later development."
- General Instruction on the Liturgy of the Hours #92
- Certain canons will call for Axion Estin to be replaced by the Irmos of the Ninth Ode.
- Here follow the Evening Prayers in places where they are said at Compline.
- Except for Wednesday of the Fifth Week. The Great Canon of Saint Andrew of Crete will have been read the evening before, and so Small Compline is appointed for that Wednesday night.
- Among the Greeks, Small Compline is served on every Friday evening of Great Lent; the Russians, however, serve Great Compline on Fridays, with some modifications (see n. 7, below). On Friday night of the Fifth Week of Great Lent, the Akathist to the Theotokos is solemnly chanted, so Small Compline on that night will be either read privately or suppressed.
- In some places, Great Compline will only be served on the first night of each of the Lesser Fasts.
- Except on Friday night, when most of these parts are read. There are also fewer prostrations on Friday night.
- On Monday through Thursday of the First Week of Great Lent, the service begins with Psalm 69, followed by the appropriate section of the Great Canon (in which case, Psalm 69 will be omitted in the Third Part).
- Or, if it is the eve of a Great Feast, the Kontakion of the day.
- On Great Feasts, the order of Great Compline ends here, and we continue the All-Night Vigil with the Litia.
- Bäumer, Histoire du Bréviaire, tr. Biron, I, 135, 147–149 et passim
- Batiffol, Histoire du bréviaire romain, 35
- Besse, Les Moines d'Orient antérieurs au concile de Chalcédoine (Paris, 1900), 333
- Bishop, "A Service Book of the Seventh Century" in The Church Quarterly Review (January, 1894), XXXVII, 347
- Butler, "The Text of St. Benedict's Rule", in Downside Review, XVII, 223
- Bresard, Luc. Monastic Spirituality. Three vols. (Stanbrook Abbey, Worcester: A.I.M., 1996)
- Cabrol, Le Livre de la Prière antique, 224.
- This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). Catholic Encyclopedia. Robert Appleton Company., s.v. Complin
- Ladeuze, Etude sur le cénobitisme pakhomien pendant le IVe siècle et la première moitié du Ve (Louvain, 1898), 288
- Pargoire, "Prime et complies" in Rev. d'hist. et de littér. relig. (1898), III, 281–288, 456–467
- Pargoire and Pétridès in Dict. d'arch. et de liturgie, s. v. Apodeipnon, I, 2579–2589
- Plaine, "La Génèse historique des Heures" in Rev. Anglo-romaine, I, 593
- —Idem, "De officii seu cursus Romani origine" in Studien u. Mittheilungen (1899), X, 364–397
- Vandepitte, "Saint Basile et l'origine de complies" in Rev. Augustinienne (1903), II, 258–264
- Warren, The Antiphonary of Bangor: an Early Irish MS. (a complete facsimile in collotype, with a transcription, London, 1893)
- —Idem, Liturgy and Ritual of the Keltic Church (Oxford, 1881)
- Liturgy of the Hours (Roman Catholic)
- The text of Compline for today's date (Roman Catholic)
- Compline of the Ordinary Form of the Roman Rite, with all Gregorian chants
- The Lutheran Service Book with Prayer Offices (LCMS)
- An Order for Compline from the 1979 Book of Common Prayer (ECUSA)
- An Office for Compline (United Methodist) (PDF)
- Night Prayer from Common Worship of the Church of England (Anglican)
- Compline from Stewardship Prayer Resources (Methodist Church) (Word format)
- Compline from Stewardship Prayer Resources (Methodist Church) (PDF - booklet format)
- Compline Choir of Saint Mark's Episcopal Cathedral, Seattle See also Wikipedia entry
- Compline Choir of Saint David's Episcopal Church, Austin
- Compline Choir of Saint Louis King of France Catholic Church, Austin
- Pacific Academy of Ecclesiastical Music
- Minnesota Compline Choir
- Pittsburgh Compline Choir
- Weekly Compline at Christ Church, New Haven, CT
- Weekly Compline at Christ Church Anglican in Savannah, GA
- St. Mary's Schola of St. Mary's Church, Arlington, VA
- Compline Choir at The Chapel of the Cross, Chapel Hill, NC