From Dom Guéranger's The Liturgical Year.

QUOD DUCE TE MUNDUS SURREXIT IN ASTRA TRIUMPHANS, HANC CONSTANTINUS VICTOR TIBI CONDIDIT AULAM.

Because the world under thy conduct has risen triumphant to the very heavens, Constantine the conqueror has built this temple in thy honour. This inscription stood in letters of gold over the triumphal arch in the ancient Vatican Basilica.[1] Never did the Roman genius frame a more magnificent utterance in so few words; never did the greatness of Simon BarJona appear to such advantage on the seven hills. In 1506 the great arch, that had looked down upon twelve centuries of prostrate pilgrims, fell from old age, and the beautiful inscription perished. But Michael Angelo's lofty dome points out to the city and the world the spot where sleeps the Galilaean fisherman, the successor of the Caesars, the Vicar of Christ, the ruler of the destinies of Rome.

The second glory of the eternal City is the tomb of St. Paul on the Ostian Way. Unlike that of St. Peter, which lies deep down in the Vatican crypt, this tomb is raised to the level of the floor by massive masonry, on which rests the great sarcophagus. This circumstance was ascertained in 1841, when the papal altar was reconstructed. It was evidently to obviate the consequences of inundations from the Tiber, that the sarcophagus had thus been raised above the place where Lucina had first laid it.[2] The pilgrim certainly finds nothing to blame in this arrangement, when, on looking through the small opening in the centre of the altar, his respectful glance falls upon the marble of the tomb, and he reads these imposing words traced in large characters of Constantine's period: PAULO APOSTOLO ET MARTYRI. To Paul Apostle and Martyr.[3]

Thus Christian Rome is protected on the North and South by these two citadels. Let us enter into the sentiments of our fathers, when they said of this privileged city: “Peter the door-keeper, sets his holy dwelling at the entrance: who can deny that this city is like heaven? At the other extremity, Paul from his temple guards the walls; Rome lies between the two: here then God dwelleth.”[4]

The present feast therefore deserves to be more than a local solemnity; its extension to the universal Church is a subject for the world's gratitude. Thanks to this feast, we can all make together in spirit today the pilgrimage ad limina Apostolorum,[5] which our ancestors performed with such fatigue and danger, yet never thought they purchased too dearly its holy joys and blessings. “Heavenly mountains, glittering heights of the new Sion! There are the gates of our true country, the two lights of the immense world. There Paul's voice is heard like thunder; there Peter withholds or hurls the bolt. The former opens the hearts of men, the latter opens heaven. Peter is the foundation-stone, Paul the architect of the temple where stands the altar by which God is propitiated. Both together form a single fountain, which pours " out its healing and refreshing waters.”[6]

In the following Lessons the Roman Church gives us her traditions concerning the two basilicas whose dedication feast we are celebrating.

Ex locis sacris quae clim apud Christianos venerationem habuerunt, illa celeberrima et frequentissima fuerunt, in quibus condita sanctorum corpora, vel aliquod Martyrum vestigium aut monumentum esset. In quorum numero sanctorum locorum, in primis semper fuit insignis es Vaticani pars, quam, sancti Petri Confessionem appellabant. Nam eo Christiani ex omnibus orbus terrae partibus, tamquam ad fidei petram et Ecclesiae fundamentum convenientes, locum Principis Apostolorum sepulchro consecratum, summa religione ac pietate venerabantur.

Illuc Constintinus Magnus imperator octavo die post susceptum baptismum venit, depositoque diademate, et humi jacens, vim lacrimarum profudit: mox sumpto ligone ac bidente terram eruit: indeque duodedim terrae cophinis, honoris causa duodecim Apostolorum, ablatis, ac loco basilicae Principis Apostolorum designate, ecclesiam aedificavit. Quam sanctus Silvester Papa decimo quarto calendas decembris, eo modo quo Lateranensem ecclesiam quinto idus novembris consecraverat, dedicavit: et in ea altare lapideum chrismate delibutum erexit; atque ex eo tempore sancivit, ne deinceps altaria nisi ex lapide fierent. Idem beatus Silvester basilicam sancti Pauli Apostoli in via Ostiensi ab eodem Constantino imperatore magnificentissime aedificatem dedicavit. Quas basilicas idem imperator multis praediis attributis locupletavit, ac muneribus amplissimis exornavit.

Porro Vaticanam basilicam vetustate jampridem collabentem, ac propterea multorum Pontificum pietate latius ac magnificentius a fundamentis erectam, Urbanus Octavus hac eadem recurrente die anni milesimi sexcentesimi vigesimi sexti, solemni ritu consecravit. Basilicam vero Ostiensem, quum dira incendi vis, anno millesimo octingentesimo vigesimo tertio penitus consumpsisset, indefessa quatuor Pontificum cura splendidius quam antea erectam, et ab interitu veluti vindicatam. Pius Nonus auspicatissimam nactus occasionem qua dogma de Immaculata beatae Mariae Virginis Conceptione nuper ab ipso proclamatum, in gentem cardinalium et episcoporum numerum ex dissitis etiam catholici orbis regionibus Roman attraxerat, die decima decembris anni millesimi octingentesimi quinquagesimi quarti, tanta circumdatus purpuratorum patrum et antistitum corona solemniter dedicavit, ejusque celebritatis memoriam hac die recolendam decrevit.
Among the holy places ve­nerated of old by the Christians, those were the most honoured and most frequented in which the bodies of the Saints were preserved, or some relic or memorial of the Martyrs. Chief among these holy places has ever been that part of the Vatican hill which was called the Confession of St. Peter. Christians from all parts of the world flocked thither, as to the rock of the faith and the foundation of the Church, and honoured with the greatest reverence and piety the spot hallowed by the sepulchre of the prince of the Apostles.

Hither on the octave day of his baptism, came the emperor Constantine the Great; and taking off his diadem, he prostrated on the ground with many tears. Then taking a hoe and mattock he broke up the earth, of which twelve basketfuls were taken away in honour of the twelve Apostles; and on the site thus marked out, he built the basilica of the Prince of the Apostles. Pope St. Sylvester dedicated it on the fourteenth of the Calens of December, just as he had consecrated the Lateran church on the fifth of the Ides of November. He erected in it a stone altar which he anointed with chrism, and decreed that thencefor­ward all altars should be made of stone. The same blessed Sylvester dedicated the basilica of St. Paul the Apostle on the Ostian Way, also magni­ficently built by the emperor Constantine, who enriched both basilicas with many estates and rich gifts and ornaments.

The Vatican basilica, however, began to decay through age; and was rebuilt from its foundations on a more extensive and magnificent scale, through the piety of several Pontiffs. It was solemnly dedicated by Urban VIII., on this day in the year 1626. In the year 1823 the Ostian basilica was burnt to the ground; but the ruins were repaired and it was rebuilt more splendidly than before, through the unwearied exertions of four Popes. Pius IX., seizing the auspicious occasion, when his Definition of the dogma of the Immaculate Conception of the blessed Virgin Mary had drawn an immense number of Cardinals and Bishops even from distant parts of the Catholic world to Rome, solemnly dedicated this basilica on the tenth of December 1854, assisted and surrounded by this noble gathering of prelates; and he decreed that the anniversary commemoration should be celebrated on this day.

In honour of the holy Apostles we gladly borrow from the libraries of our Anglican brethren the following Sequence, sung four centuries ago by the venerable church of York.

Sequence

In sollemni memoria
Apostolorum principis,
Piae laudis harmonia
Laetis resonet canticis.

Veneremur simul pari
Dignum lade venerari apostolum gentium;
Ut quos amor vita junxit,
Nec mors ipsa post disjunxit jungat et praeconium.

Horum laus est quod destructa
Romanae potentiae idolatria,
Jam fundata et firmata
Ibidem orbem gubernat Ecclesia.

Fide Petri fundamentum
Pauli tenet firmamentum dogmate Ecclesia;
Clavis huic potentiae,
Illi cessit scientiae juncta ad officia.

Petro namque sub pastore
Gratulatur et rectore inter fluctus saeculi;
Pauli viget ex doctrina,
Vitae sumpta medicina grex fidelis populi.

Iste verbo instruit,
Ille coelum aperit verbo vitae credulis,
Et quod unus praedicat
Alter verum comprobat crebris hoc miraculis.

Hic Judaeos, ille gentes
Viam vitae nescientes ad salutem convocat;
Ambo praesunt convocatis,
Ambo certant desolatis, hostis ne prevaleat.

Contra summae potentiae
Consurgunt imperium,
Unus crucis, alter ensis
Perpessus supplicium.

Sicque una urbe mortem
Una die passi, sortem ad justorum transmeant;
Qui malorum noe exsortes
Sua prece et consortes beatorum faciant.

Amen.
On this solemn commemoration
of the Prince of the Apostles,
let the harmony of our loving praise
resound in joyous canticles.

With him let us also honour
the Apostle of the Gentiles, worthy of equal praise;
that those whom love united in life,
and death itself did not sever, may together receive our homage.

Their praise consists in this,
that the idolatry of the Roman empire has been destroyed;
and in that same Rome the Church
has been founded and built up, and rules the world.

The Church is founded on Peter's faith,
and strengthened by Paul's teaching;
one holds the key of authority,
the other that of knowledge, both for the same work.

With Peter for their shepherd and guide,
the faithful people rejoice amid the billows of this world;
while they grow strong
and receive life-giving medicine from Paul's doctrine.

Paul instructs them by his word,
Peter opens heaven to believers in the word of life,
and what the one preaches
the other proves by many miracles.

One calls the Jews to salvation, the other the Gentiles
ignorant of the way of life;
together they direct the called,
together they strive lest the enemy should prevail against them.

They stand against the highest power of the empire,
and incur the penalty,
one of the cross,
the other of the sword.

Thus they suffer death in the same city,
on the same day, and together pass to the reward of the just;
by their prayer may they deliver us from all evil,
and make us companions of the blessed.

Amen.

Today let us call to mind and complete the instructions we received on the general feast of the Dedication of churches; and let us conclude with the following Sequence, worthy of the pen of Adam of St. Victor, to whom it was long attributed. It sets forth in all the figures once so well known, the great mystery of Christ's union with the human race, which is expressed in the consecration of Christian temples.

Sequence

Quam dilecta tabernacula
Domini virtutum
et atria!

Quam electi Architecti,
Tuta aedificia, quae non movent
Imo fovent vectus, flumen, pluvia!

Quam decora fundamenta
Per concinna sacramenta
Umbrae praecurrentia!

Latus dae dormientis
Evam fundit, in manentis
Copulae primoria.

Arca ligno fabricata
Noe servat, gubernata
Mundi per diluvium.

Prole sera tandem foeta
Anus Sara ridet laeta,
Nostrum lactans gaudium.

Servus bibit qui legatur
Et camelus adaquatur
Ex Rebeccae hydria.

Haec insures et armillas
Aptat sibi, ut per illas
Virgo fiat congrua,

Synagoga supplantatur
A Jacob, dum devagatur
Nimis freta litterae.

Liam lippam latent multa:
Quibus Rachel videns fulta,
Pari nubit foedere.

In bivio tegens nuda,
Geminos parit ex Juda
Thamar diu vidua.

Hic Moyses a puella
Dum se lavat, in fiscella
Reperitur scirpea.

Hic mas agnus immolatur
Quo Israel satiatur,
Tinctus ejus sanguine;

Hic transitur rubens unda,
Egyptios sub profunda
Obruens voragine.

Hic est urna manna plena,
Hic mandata legis dena,
Sed in arca foederis.

Hic sunt aedis ornaments,
Hic Aaron indumenta
Quae praecedit poderis.

Hic Urias viduatur,
Bethsabee sublimatur,
Sedis consors regiae.

Haec regi varietate
Vestis astat deauratae,
Sicut regum filiae.

Huc venit Austri regina,
Salomonis quam divina
Condit sapientis,

Haec est nigra sed formosa,
Myrrhae et thuris fumosa,
Virga pigmentaria.

Haec futura
Quae figura obumbravit,
Reseravit nobis die gratiae;

Jam in lecto cum dilecto quiescamus,
Et peallamus:
Adsunt enim nuptiae.

Quarum tonat initium
In tubis epulantium
Et finis per pealterium.

Sponsum millena millia
Una canunt melodia,
Sine fine dicentia: Alleluia!

Amen.
How lovely are the tabernacles
and courts of the Lord
of hosts!

So firmly is the temple built by the incomparable architect,
that wind and flood
and rain instead of shaking  strengthen it.

Beauteous are its foundations,
aptly prefigured by the mysteries
of the time of shadows!

While Adam sleeps
Eve comes forth from his side,
the first type of an eternal union.

The ark, built of wood,
preserves Noe, safely sailing
through the deluge that destroys the world.

Sara, advanced in years,
laughs joyously to see herself a mother
suckling the child whose name signifies our joy.

The servant sent as ambassador
drinks from Rebecca's pitcher,
and she waters his camels;

then she adorns herself
with ear-rings and bracelets,
that she may appear as beseems a virgin.

The synagogue, wandering away
and trusting too much to the letter,
is supplanted by Jacob.

Many things lie hid from blear-eyed Lia,
which are a strength to Rachel the clear-sighted,
and give her equal rights.

Thamar, long a widow,
veils herself on the highway,
and gives twin sons to Juda.

Moses, in a wicker-basket,
is found by the maiden
as she is bathing.

The male lamb being im­molated,
the Israelites are fed therewith,
and are marked with its blood.

They cross the Red Sea,
whose rushing waves
engulf the Egyptians.

Here is the urn full of manna;
here in the Ark of the Covenant
are the ten commandments of the Law.

Here are the ornaments of the temple;
here the garments of Aaron,
and first of them all the Pontiff's ephod.

Bethsabee, widow of Urias, 
is raised as bride
even to share the royal throne,

and stands before the king
in robes of gold and all variety,
even as the daughters of princes.

Hither comes the queen of the South,
whom Solomon instructs
with his divine wisdom;

Though black, she is beautiful,
breathing the fragrance of myrrh
and incense and every perfume.

These future things
foreshadowed thus in figures,
the day of grace has revealed to us;

Let us rest in peace
with the Beloved and sing to him,
for it is the Nuptial-day.

The feast was opened
by the clang of trumpets,
and closes with the psaltery.

Millions of voices hail the Spouse
with one same melody,
repeating without end: Alleluia!

Amen.

[1] De Rossi, Inscript. Christ. T. II. 345.
[2] See the Legend of St. Cornelius, Sept. 16th.
[3] Dom Gueranger, Saint Cécile et la Société romaine aux deux premiers siècles, ch vi.
[4] Janitor ante fores fixit sacraria Petrus: Quis neget has arces instar esse poli? Parte alia Pauli circumdant atria muros: Hos inter Roma est: hic sedet ergo Deus. Inscription on the gate of Rome which was called n the 6th century the gate of St. Peter. (DE ROSSI, INSCRIPT. ii. 99.)
[5] To the threshold of the Apostles, i. e. of their basilicas, where pilgrims used to prostrate before entering.
[6] Venant. Fortunat. Miscellania, iii. 7.