Christmas (December 25)

Etymology and vocabulary

In French, Noël derives from Old French Noel / Naël, from popular Latin natalis (dies) domini: "the day of the birth of the Lord"^[5]. In Old French, Noël! was also a popular cry of joy, known in English as Nowell. The English word Christmas comes from the Old English Crīstesmæsse, "the Mass of Christ"^[6]. In liturgical Latin, the feast is designated Nativitas Domini or In Nativitate Domini in the liturgical books, a title still used today in the Roman Missal.

Liturgical rank: a solemnity, not a mere feast

In the hierarchy of celebrations of the Latin Church (solemnities, feasts, obligatory memorials, optional memorials), fixed by the Universal Norms on the Liturgical Year and the Calendar (1969), Christmas holds the highest rank: that of solemnity^[7]. This rank is not honorific: it concretely determines the richness of the liturgy (a Mass with three formularies, a proper preface, the Gloria and Creed sung, an octave) and the precedence of the feast over any other event of the calendar that would fall on the same day. Only Easter and a few other solemnities of the Lord (Epiphany, Ascension, Pentecost) share with Christmas this status as a summit of the liturgical year. The obligation to attend Mass, for its part, does not derive from this rank: it comes from canon 1246 of the Code of Canon Law^[8].

Christmas in the liturgical year: between Advent and Epiphany

Christmas cannot be understood in isolation: it is the point of arrival of the season of Advent, those four weeks of waiting that prepare hearts for the coming of the Saviour, and the point of departure of Christmastide, which traditionally extends until the feast of the Baptism of the Lord. The detailed place of Christmas in the overall architecture of the liturgical year — its two great temporal and sanctoral cycles, its hierarchy of colours and ranks — is developed in its own right in the article The liturgical year; the present article concentrates on the solemnity of Christmas in particular.

Within Christmastide, two dates structure the whole: January 1, the solemnity of Holy Mary, Mother of God, which closes the octave of the Nativity on the eighth day, and January 6, the feast of the Epiphany, which celebrates the manifestation of Christ to the nations through the adoration of the Magi — an episode narrated by Saint Matthew and not developed in detail here, since it is the subject of its own article.

A holy day of obligation

Canon law classes Christmas among the days on which Catholic faithful are bound to attend Mass. Canon 1246 § 1 of the 1983 Code of Canon Law provides:

"Sunday, on which, by apostolic tradition, the paschal mystery is celebrated, must be observed in the whole Church as the principal holy day of obligation. And likewise must be observed the days of the Nativity of Our Lord Jesus Christ, of the Epiphany, of the Ascension and of the most Holy Body and Blood of Christ, [...]" — Code of Canon Law (1983), canon 1246 § 1^[9]

This list takes up that of canon 1247 of the 1917 Code, which already bore the same ten feasts; the great reduction in the number of holy days of obligation dates from Saint Pius X, in 1911 (from 36 to 8 feasts)^[10]. In France, four feasts remain of obligation: Christmas, the Ascension, the Assumption and All Saints. This situation goes back to the indult of Cardinal Caprara, papal legate, of April 9, 1802, which transferred to Sunday Epiphany, Corpus Christi and the feast of Saints Peter and Paul^[11]. Christmas thus remains, in this list as in the universal list, one of the solemnities which every Catholic is bound to celebrate by participation in the Eucharist.

The Christmas liturgy is not a pure ecclesial construction: it proclaims and makes present two precise Gospel narratives, that of Saint Luke and that of Saint Matthew, which complement without contradicting each other and which both ground the readings assigned to the three Masses of the day.

The narrative of Saint Luke: the census and the manger

It is Luke's Gospel which gives the most detailed account of the night of Bethlehem: on the occasion of a census edict of Caesar Augustus, Joseph goes up from Nazareth to Bethlehem with Mary, his wife, who is with child; the day of the delivery comes while they are there, and Mary "wrapped him in swaddling clothes and laid him in a manger, because they had no room in the inn" (Luke 2:7)^[12].

The narrative continues with the announcement made to the shepherds by an angel, then by the multitude of the heavenly host singing "Glory to God in the highest, and on earth peace among men with whom he is pleased" (Luke 2:14)^[13] — the verse which would become the Gloria of the Roman Mass. Luke explicitly mentions the census ordered under the governorship of Quirinius in Syria (Luke 2:2), a chronological detail which has raised, since the 19th century, a repeated critical objection: the known data on the governorship of Quirinius (legate of Syria around AD 6-7) seem difficult to reconcile with the birth of Jesus under the reign of Herod the Great, who died in 4 BC.

Several serious harmonising solutions have been proposed and deserve to be taken seriously rather than dismissed out of hand as an apologetic contrivance. The archaeologist William M. Ramsay brought forward a fragmentary Latin inscription, the Lapis Tiburtinus, which could attest a first command of Quirinius in Syria earlier than that of AD 6, which would make Luke's text exact as it stands^[14]. Other exegetes have proposed translating the Greek of Luke 2:2 (hautē apographē prōtē egeneto hēgemoneuontos tēs Syrias Kyrēniou) not as "This census was the first, [...] while Quirinius was governor", but as "This census took place before Quirinius was governor", a grammatically defensible reading of the comparative prōtē^[15]. Finally, Tertullian, writing around 207-208, independently attests a census of Judea under Sentius Saturninus, governor of Syria from 9 to 6 BC — that is, under the effective reign of Herod —, which at minimum confirms the existence of regular Roman censuses in the region at the supposed time of Christ's birth^[16]. None of these solutions carries definitive archaeological proof, but their convergence suffices to show that the objection is not the final word on the debate that part of sceptical popularisation too hastily makes of it.

The narrative of Saint Matthew: the Magi and the star

Matthew's Gospel completes the Lucan narrative with a second tableau: Jesus having been born at Bethlehem of Judea in the days of King Herod, wise men from the East arrive at Jerusalem and ask where the new-born king of the Jews is: "We have indeed seen his star at its rising" (Matthew 2:2)^[17].

The coming of the Magi guided by a star to adore the child and offer him gold, frankincense and myrrh (Matthew 2:1-12), then the flight into Egypt before Herod's persecution (Matthew 2:13-15), complete the Lucan tableau. This episode, rich in historical questions (identity of the Magi, nature of the star, chronology of the Massacre of the Innocents), is developed in its own right in the article devoted to the Epiphany, a distinct liturgical feast which specifically commemorates the manifestation of Christ to the nations through the adoration of the Magi; it is mentioned here only insofar as it forms, like Luke's narrative, part of the scriptural foundation of the mystery of Christmas.

The historicity of the infancy narratives in the face of modern criticism

Part of contemporary exegesis, following Rudolf Bultmann, has proposed reading the infancy narratives of Luke and Matthew as late theological compositions, largely legendary, constructed after the event to illustrate biblical themes (new Exodus, new Moses, fulfilment of the prophecies) rather than as accounts of real events^[18]. This reading deserves to be taken seriously in its arguments, but it cannot have the last word. It rests largely on a methodological presupposition — the a priori improbability of the miraculous and the providential — rather than on positive proof of literary invention; it also underestimates the coherence of the two narratives, independent of each other in their composition, on the essential points (birth at Bethlehem, under Herod, of Mary a virgin, then at Nazareth); and it tends to treat every detailed circumstance (the census, the governor, the manger) as suspect on principle, even though this wealth of verifiable detail is precisely what characterises a narrative rooted in historical memory rather than a pure edifying fable. The Catholic Church, without requiring belief that each narrative detail is reported with the precision of a modern court record, firmly holds the historical reality of the virginal birth of Jesus at Bethlehem of Judea, under the reign of Herod: the Creed confesses the virginal birth ("born of the Virgin Mary") and anchors the life of Christ in a dated history ("under Pontius Pilate"); the birth at Bethlehem, reported by Matthew and Luke, is taken up by the Fathers as early as the 2nd century (Justin)^[19][20].

The date of December 25 is fixed with certainty only from the 4th century. The oldest document attesting it as a liturgical feast is the Chronograph of 354, a richly illuminated Roman almanac, whose Depositio Martyrum section — a list of the liturgical anniversaries of the Church of Rome — bears, on its very first line:

"VIII of the calends of January: birth of Christ at Bethlehem of Judea." — Chronograph of 354, Depositio Martyrum^[21]

"VIII of the calends of January" corresponds, in Roman reckoning, to December 25. Historians agree in tracing this Roman usage back to the year 336, to which the base list of the document refers^[22]. Earlier still, at the beginning of the 3rd century, the Commentary on Daniel attributed to Hippolytus of Rome (c. 204) contains, according to some manuscripts, a passage which likewise situates the birth of Christ on December 25 — a passage whose authenticity and dating remain actively discussed by contemporary textual criticism^[23].

Two great scholarly explanations have confronted each other for over a century to account for the choice of this date: the hypothesis of a borrowing from a feast of the unconquered Sun on December 25, often attributed to Emperor Aurelian (274) but attested only from the mid-4th century (the games of the Sun instituted by Aurelian being held in October, according to S. Hijmans), and the hypothesis of a theological calculation internal to early Christianity, connecting the date of the Passion (traditionally fixed on March 25) to that of the conception, then of the birth of Christ nine months later. The passage of Hippolytus (c. 204), if it is authentic, is in any case earlier than Aurelian^[24]. This debate, its precise sources (Tertullian, Julius Africanus, Saint Augustine, the treatise De solstitiis) and the current state of research are set out in detail, with all their nuances, in the dedicated article Why is Christmas celebrated on December 25?: the reader who wishes to explore this precise question will find a complete treatment there. What matters for the history of the feast itself, retraced below, is that December 25 first established itself at Rome, before gradually reaching the whole of Christendom.

Rome and the Latin West, home of the fixing on December 25

It is therefore at Rome, in the course of the 4th century, that the feast of the Nativity on December 25 is best attested and, very probably, where it was born as a distinct liturgical feast. The Latin West — North Africa, Gaul, Spain — rapidly adopted this Roman usage in the wake of the growing authority of the Apostolic See over the Latin Churches.

The slow adoption in the East: the testimony of Saint John Chrysostom

In the East, the oldest tradition joined the birth and the manifestation of Christ (Theophany) in one and the same feast, celebrated on January 6. The separation between a feast of the Nativity on December 25 and a feast of the Epiphany on January 6 appears there only towards the end of the 4th century. The most explicit testimony of it is a homily of Saint John Chrysostom, preached at Antioch on December 25, 386:

"It is not yet ten years since this day has been clearly known among us, whereas it has long been known to the inhabitants of the West." — Saint John Chrysostom, In diem natalem Domini nostri Jesu Christi, Antioch, 386 (Patrologia Graeca 49, 351)^[25]

Chrysostom explains to his hearers that this feast of December 25, known "for a long time" in the West, has been clearly known at Antioch for less than ten years, and he defends its authenticity by relying on the authority of Roman usage^[26]. The direction of the spread is thus clearly established: from Rome towards the East, and not the reverse. Roman usage is attested as early as 336 and Antioch adopts it around 376-377, some forty years later; Constantinople (Gregory of Nazianzus, December 25, 380) and Cappadocia (feast attested in 380 by Gregory of Nyssa) are contemporary with Antioch. Only Egypt (between 427 and 433) and Jerusalem (later still) belong to the 5th century or beyond.

The Armenian exception: a Theophany kept on January 6

A single great Eastern Christian tradition has never adopted the separation between the Nativity (December 25) and Epiphany (January 6): the Armenian Apostolic Church. The two facts must be correctly dated: the separation had already spread in the East by the end of the 4th century, as attested by Chrysostom's homily at Antioch in 386 quoted above; the Armenian isolation, for its part, is a matter of the 5th century. At war against the Sassanid Persians — defeat at Avarayr on May 26, 451, under Vardan Mamikonian — Armenia could not be represented at the Council of Chalcedon, opened in October 451, and its own reception of the century's Christological debates lastingly kept it apart from the disciplinary evolution of the other Churches^[27]. It therefore continues to celebrate on January 6 a single feast of the Theophany, which joins the birth of Christ, his manifestation to the Magi, and his baptism in the Jordan — three mysteries which the Latin rite and the other Eastern Churches distribute over several distinct days^[28].

The Julian calendar gap: the "Orthodox Christmas" of January 7

A second factor, purely calendrical and not doctrinal, explains why a significant part of the Orthodox world celebrates Christmas not on December 25 of the Gregorian calendar, but on January 7. Certain Orthodox Churches — Russian, Serbian, Georgian, as well as the Patriarchate of Jerusalem and the Coptic Church — have kept for their liturgical calendar the Julian calendar, which remained in civil use until the Gregorian reform of 1582 and for a time afterwards in several Orthodox countries. The Julian calendar accumulates, relative to the Gregorian calendar, a gap of about thirteen days in the 21st century: December 25 in the Julian calendar thus corresponds to January 7 of the Gregorian calendar commonly used in the West. It is therefore not a theologically different date, but the same December 25, reckoned in a different civil calendar.

Beyond its date, what makes Christmas singular in the Roman liturgical calendar is the intrinsic richness of its celebration: a feast with three Masses, a solemn proclamation of its own, and a full octave.

The three Masses: night, dawn and day

From the end of the 6th century onward, Roman usage distinguishes three Masses for Christmas Day, each with its own texts, its own Gospel, and, originally, its own place of celebration ("station") in Rome^[29]. The Mass of the day, the oldest, remained celebrated at Saint Peter's until around 1143. The night Mass was welcomed at Saint Mary Major, at the oratory of the Crib, after Pope Saint Sixtus III had the basilica rebuilt around 435-440, in the Marian impetus of the Council of Ephesus (431)^[30]. The dawn Mass, celebrated at daybreak in honour of Saint Anastasia, a martyr dear to the Byzantine colony of Rome, was added third in the 6th century; it comes between midnight Mass and the Mass of the day^[31]. The three Masses are attested from the end of the 6th century by Saint Gregory the Great (Homily 8 on the Gospels: "missarum solemnia ter hodie celebraturi sumus").

This liturgical triptych is not a redundant duplication: it unfolds the mystery by degrees — the birth in the night of the world, its manifestation to the first witnesses at dawn, its theological proclamation in broad daylight in the great Johannine Prologue^[32]. A Catholic is bound by the Sunday precept to only one attendance at Christmas Mass; but the tradition of attending several of these Masses in succession, particularly midnight Mass, remains a widely observed practice of piety.

The Proclamation of the Nativity (the "Kalenda")

On Christmas Eve, or just before midnight Mass, the Roman Martyrology provides a solemn text traditionally called the Kalenda or Proclamation of the Nativity, which inscribes the birth of Christ in the whole of salvation history, from the creation of the world to the reign of Augustus:

"The twenty-fifth day of December, when ages beyond number had run their course from the creation of the world, when God in the beginning created heaven and earth, and formed man in his own likeness; when century upon century had passed since the Almighty set his bow in the clouds after the Great Flood, as a sign of covenant and peace; in the twenty-first century since Abraham, our father in faith, came out of Ur of the Chaldees; in the thirteenth century since the People of Israel were led by Moses in the Exodus from Egypt; around the thousandth year since David was anointed King; in the sixty-fifth week according to the prophecy of Daniel; in the hundred and ninety-fourth Olympiad; in the seven hundred and fifty-second year since the foundation of the City of Rome; in the forty-second year of the reign of Caesar Octavian Augustus, the whole world being at peace, Jesus Christ, eternal God and Son of the eternal Father, desiring to consecrate the world by his most loving presence, was conceived by the Holy Spirit, and when nine months had passed since his conception, was born of the Virgin Mary in Bethlehem of Judah. The birthday of Our Lord Jesus Christ according to the flesh." — Proclamation of the Nativity, Roman Martyrology^[33]

This text, sung in a particular tone belonging to this one proclamation alone in the year, deliberately situates the event of Bethlehem at the intersection of biblical chronology (creation, Flood, Abraham, the Exodus, David), profane Greek chronology (the Olympiads) and Roman chronology (foundation of Rome, reign of Augustus): Christmas is not a timeless myth, but an event dated at the crossroads of several historical memories, Jewish, Greek and Roman — a reading in keeping with the received traditional interpretation of biblical chronology: held, tenable and defensible, it situates the birth of Christ at the end of a real history whose milestones the Church confesses (creation, Flood, Abraham, Exodus, David), without erecting each figure of this solemn reckoning into a magisterial definition — see the article Is the World Only 6,000 Years Old?.

The vigil and the octave of Christmas

December 24, the day of the Christmas vigil, has its own Mass and its own formulary, distinct from the three Masses of the 25th. The solemnity itself is accompanied by an octave: the eight days opening on December 25 are celebrated as an extension of the same feast, with a particular place for the feast of the Holy Family (Sunday within the octave) and, on January 1, for the solemnity of Holy Mary, Mother of God, which closes the octave on the affirmation of the divine motherhood of Mary — a dogma defined at the Council of Ephesus in 431^[34]. The whole of Christmastide, begun on December 25, then extends until the feast of the Baptism of the Lord.

The great patristic homilies of Christmas

The Roman liturgy of Christmas Matins preserves, in the old breviary, extracts of patristic homilies preached for this feast, which testify to the antiquity and depth of theological reflection on the Incarnation. Saint Leo the Great, pope from 440 to 461, thus concludes one of his sermons for the Nativity with an exhortation that has remained famous:

"Christian, remember your dignity, and now that you share in God's own nature, do not return by sin to your former base condition. Bear in mind who is your Head and of whose Body you are a member." — Saint Leo the Great, Sermon 21, In Nativitate Domini I^[35]

This text, still read today at the Office of Readings for Christmas Day in the Liturgy of the Hours, sums up the spiritual stake of the feast: the Incarnation of the Son of God is not a mere past event to commemorate, but a mystery which raises human nature itself, by making it, through grace, a sharer in the divine nature.

Theological meaning: the mystery of the Incarnation

The theology of Christmas is summed up in the Catechism of the Catholic Church by bringing to light the paradox of divine humility:

"Jesus was born in the humility of a stable, into a poor family; simple shepherds were the first witnesses to the event. It is in this poverty that heaven's glory is made manifest." — Catechism of the Catholic Church, § 525^[36]

"The mystery of Christmas is fulfilled in us when Christ 'takes form' in us (Gal 4:19)." — Catechism of the Catholic Church, § 526^[37]

The complete doctrinal development of the mystery of the Incarnation — why God became man, in what precisely consists the union of the two natures in the person of the Word, how this dogma was defined and defended against the ancient Christological heresies — is treated in its own right in the article How to explain the Incarnation simply?; Christmas is its annual liturgical celebration, not the place of its complete theological exposition.

While the proper liturgy of Christmas remains, for the most part, the affair of the clergy and the liturgical books, a devotional tradition came, from the 13th century onward, to give the feast a lasting popular face: the crib.

Saint Francis of Assisi at Greccio (1223)

At Christmas 1223, Saint Francis of Assisi organised, in a cave in the mountains of Greccio, in Latium, what is regarded as the first living crib in Christian history. His earliest biographer, Brother Thomas of Celano, reports that Francis wanted:

"I would like to represent the Child born at Bethlehem, and see with the eyes of the body the hardships in which he found himself for lack of what a newborn needs, when he was laid in a manger on straw between the ox and the ass." — Thomas of Celano, Vita Prima Sancti Francisci (1228-1229), account of the Christmas at Greccio (Vita prima 84)^[38]

Unlike later cribs, Greccio's had neither a statue of the Christ Child, nor figures of Mary and Joseph: only a manger filled with straw, a very real ox and ass made up the scene, around a portable altar at which midnight Mass was celebrated. Thomas of Celano reports that Francis, a deacon, sang the Gospel there and preached with such emotion that one of those present, a virtuous man, saw in the manger a little child as if lifeless, whom the saint awoke^[39]. According to Saint Bonaventure, Francis had sought and obtained from the Sovereign Pontiff (Honorius III) permission to organise the celebration^[40]. In 2023, on the occasion of the eight hundredth anniversary of this event, Pope Francis devoted the whole of his Wednesday catechesis of December 20 to it, seeing in it a "school of sobriety and joy"^[41].

The relic of the manger at Saint Mary Major

Rome preserves, independently of the Greccio crib, an older tradition: that of a material relic of the manger of Bethlehem. Under the pontificate of Saint Theodore I (642-649), when the advance of the Arab-Muslim conquests threatened the Holy Land, fragments of wood — traditionally identified as planks of the manger of Bethlehem — are said to have been transferred to Rome and deposited in the basilica of Saint Mary Major, which thenceforth received the title of Sancta Maria ad Praesepe ("Holy Mary at the Manger")^[42]. This relic, kept in the confession of the basilica beneath the papal altar, today takes the form of fragments of wood attributed by tradition to the cradle of Christ^[43]. The presence of this relic confirmed Saint Mary Major as the place of the Christmas night Mass, celebrated at the oratory of the Crib; the Mass of the day remained at Saint Peter's until around 1143, before being itself transferred to Saint Mary Major in the 12th century.

From Greccio to family cribs

The usage of Greccio spread first in Franciscan circles, before reaching the whole of Catholic Europe from the 15th-16th century onward, in progressively enriched forms: sculpted figurines at Naples (the presepe napoletano, teeming with figures of everyday Neapolitan life around the biblical scene), clay santons in Provence from the French Revolution onward — when closed churches pushed the faithful to set up the crib at home —, or monumental cribs in the great Roman basilicas at Christmas^[44]. This diversity of forms testifies to a single intuition: to make visible and close at hand, in the home or in the public square, what the liturgy proclaims in the sanctuary.

The Christmas tree, a distinct tradition

The crib, a Catholic tradition of Franciscan origin directly linked to the liturgy and to Scripture, should not be confused with the Christmas tree, whose history is different. The earliest written trace often cited goes back to the account books of Sélestat, in Alsace, in 1521 — trees for Christmas, with no description of ornament^[45]; the earliest surviving description of a decorated tree dates from 1605, at Strasbourg, and the interpretation of these milestones remains debated among historians. The usage developed in a region that had become a centre of the Protestant Reformation; it has been seen, as a hypothesis, as the effect of a reluctance in Reformed circles towards the figured representation of the Nativity, which is said to have favoured a non-figurative symbol of the feast^[46]. The Christmas tree is therefore not, originally, a Catholic liturgical tradition in the same way as the crib: its universal spread, including in Catholic homes, is a later and largely cultural phenomenon, which coexists today with the crib without replacing its own theological meaning.

Midnight Mass and the great Roman celebrations

Midnight Mass remains, in contemporary Catholic piety, the most attended moment of the liturgical year after the great paschal feasts: in many dioceses, faithful who do not practise regularly throughout the year go there specifically, a sign of the unique symbolic place Christmas keeps even in a largely secularised society. At Rome, the Christmas night Mass presided over by the Pope in Saint Peter's Basilica remains one of the most followed celebrations of the universal liturgical year, broadcast around the world.

Secularisation and spiritual rediscovery

Christmas is, in the contemporary world, the most universally recognised Christian feast socially — and, paradoxically, one of those whose properly religious content is most exposed to commercial and cultural dilution. This tension is not new: it already existed, in other forms, in late Antiquity, when Saint Leo the Great had to reprove Roman faithful who, before entering Saint Peter's, turned round out of habit to salute the rising sun^[47]. The response of the Church, then as today, has never been to give up the date or the feast, but constantly to recall, through the liturgy itself — the three Masses, the solemn proclamation, the great patristic readings —, that what is celebrated is not the return of natural light, but the coming, in the flesh, of Him by whom "All was made through him, and without him nothing was made" (John 1:3)^[48].

• Why is Christmas celebrated on December 25? — the complete historical debate on the origin of the date: the calculation hypothesis and the borrowing-from-Sol-Invictus hypothesis.
• Why does Advent exist? — the season of waiting that prepares Christmas.
• How to explain the Incarnation simply? — the theological mystery celebrated by the Nativity.
• The liturgical year — the place of Christmas in the calendar of the Church as a whole.
• Epiphany — the manifestation of Christ to the Magi, celebrated on January 6.
• Baptism of the Lord — the feast which closes Christmastide.
• Holy Mary, Mother of God (January 1) — the solemnity which closes the octave of Christmas.
• Saint Francis of Assisi — the inventor of the living crib of Greccio.
• Corpus Christi (Fête-Dieu) — another great solemnity instituted by the liturgical history of the Latin Church.
• The Church of the Nativity in Bethlehem — the very place the feast commemorates.

Main sources

• Jerusalem Bible, Gospels according to Saint Luke, Saint Matthew and Saint John (the narratives of Luke 2 and Matthew 2 are paraphrased; the passages quoted follow this translation).
• Chronograph of 354 (Calendar of Filocalus), ed. Theodor Mommsen, Chronica Minora saec. IV. V. VI. VII., vol. I, MGH Auctores Antiquissimi IX, Berlin, 1892, pp. 71-72.
• Saint John Chrysostom, In diem natalem Domini nostri Jesu Christi (homily of December 25, 386), Patrologia Graeca 49, col. 351-362.
• Code of Canon Law (1983), canon 1246; Code of Canon Law (1917), canon 1247.
• Thomas of Celano, Vita Prima Sancti Francisci (1228-1229), English rendering after the edition established in Saint François d'Assise, Écrits, Vies, Témoignages, ed. J. Dalarun, Éditions franciscaines / Cerf, 2010.
• Saint Leo the Great, Sermones, ed. R. Dolle, Sources chrétiennes 22, 49, 74, 200, Cerf, 1947-1973.
• Catechism of the Catholic Church, §§ 522-526, 1171.
• Roman Martyrology, Proclamation of the Nativity ("Kalenda").
• Vatican.va, catechesis of Pope Francis, general audience of December 20, 2023.