St. Peter, apostle
29-Jun

From Butler's Lives of the Saints 1894:
PETER was of Bethsaida in Galilee, and as he was fishing on the lake was called by Our Lord to be one of His apostles. He was poor and unlearned, but candid, eager, and loving. In his heart, first of all, grew up the conviction, and from his lips came the confession, "Thou art the Christ, the Son of the living God;" and so Our Lord chose him, and fitted him to be the Rock of His Church, His Vicar on earth, the head and prince of His apostles, the centre and very principle of the Church's oneness, the source of all spiritual powers, and the unerring teacher of His truth. All Scripture is alive with him; but after Pentecost he stands out in the full grandeur of his office. He fills the vacant apostolic throne; admits the Jews by thousands into the fold; opens it to the Gentiles in the person of Cornelius; founds, and for a time rules, the Church at Antioch, and sends Mark to found that of Alexandria. Ten years after the Ascension he went to Rome, the centre of the majestic Roman Empire, where were gathered the glories and the wealth of the earth and all the powers of evil. There he established his Chair, and for twenty-five years labored with St. Paul in building up the great Roman Church. He was crucified by order of Nero, and buried on the Vatican Hill. He wrote two Epistles, and suggested and approved the Gospel of St. Mark. Two hundred and sixty years after St. Peter's martyrdom came the open triumph of the Church. Pope St. Sylvester, with bishops and clergy and the whole body of the faithful, went through Rome in procession to the Vatican Hill, singing the praises of God till the seven hills rang again. The first Christian emperor, laying aside his diadem and his robes of state, began to dig the foundations of St. Peter's Church. And now on the site of that old church stands the noblest temple ever raised by man; beneath a towering canopy lie the great apostles, in death, as in life, undivided; and there is the Chair of St. Peter. All around rest the martyrs of Christ—Popes, Saints, Doctors, from east and west—and high over all, the words, "Thou art Peter, and on this Rock I will build My Church." It is the threshold of the apostles and the centre of the world.

From Butler's Lives of the Saints 1895:
THE CHAIR OF ST. PETER AT ANTIOCH.

Baronius, Annot. In Martyrol. ad 18 Januarii, the Bollandists, ib. t. 2
p. 182, sect. 5 and 6, and especially Jos. Bianchini, Dissecr. De Romana
Cathedra in notis in Anastatium Biblioth. t. 4, p. 150.

THAT Saint Peter, before he went to Rome, founded the see of Antioch, is
attested by Eusebius,[1] Origen,[2] St. Jerom,[3] St. Innocent,[4] Pope
Gelasius, in his Roman Council,[5] Saint Chrysostom, and others. It was
just that the prince of the apostles should take this city under his
particular care and inspection, which was then the capital of the East,
and in which the faith took so early and so deep root as to give birth
in it to the name of Christians. St. Chrysostom says, that St. Peter
made there a long stay: St. Gregory the Great,[6] that he was seven
years bishop of Antioch; not that he resided there all that time, but
only that he had a particular care over that church. If he sat
twenty-five years at Rome, the date of his establishing his church at
Antioch must be within three years after our Saviour's ascension; for in
that supposition he must have gone to Rome in the second year of
Claudius.

The festival of St. Peter's chair in general, Natale Petri de Cathedra,
is marked on this day in the most ancient calendar extant, made in the
time of pope Liberius, about the year 354.[7] It also occurs in
Gregory's sacramentary, {443} and in all the martyrologies. It was kept
in France in the sixth century, as appears from the council of Tours,[8]
and from Le Cointo.[9]

* * * * *

In the first ages it was customary, especially in the East, for every
Christian to keep the anniversary of his baptism, on which he renewed
his baptismal vows, and gave thanks to God for his heavenly adoption:
this they called their spiritual birthday. The bishops in like manner
kept the anniversary of their own consecration, as appears from four
sermons of St. Leo, on the anniversary of his accession or assumption to
the pontifical dignity, and this was frequently continued by the people
after their decease, out of respect to their memory. St. Leo says, we
ought to celebrate the chair of St. Peter with no less joy than the day
of his martyrdom; for as in this he was exalted to a throne of glory in
heaven, so by the former he was installed head of the church on
earth.[10]

On this festival we are especially bound to adore and thank the divine
goodness for the establishment and propagation of his church, and
earnestly to pray that in his mercy he preserve the same, and dilate its
pale, that his name may be glorified by all nations, and by all hearts,
to the boundaries of the earth, for his divine honor and the salvation
of souls, framed to his divine image, and the price of his adorable
blood. The church of Christ is his spiritual kingdom: he is not only the
architect and founder, but continues to govern it, and by his spirit to
animate its members to the end of the world as its invisible head:
though he has left in St. Peter and his successors a vicar, or
lieutenant, as a visible head, with an established hierarchy for its
exterior government. If we love him and desire his honor, if we love men
on so many titles linked with us, can we cease weeping and praying, that
by his sweet omnipotent grace he subdue all the enemies of his church,
converting to it all infidels and apostates? In its very bosom sinners
fight against him. Though these continue his members by faith, they are
dead members, because he lives not in them by his grace and charity,
reigns not in their hearts, animates them not with his spirit. He will
indeed always live by grace and sanctity in many members of his mystical
body. Let us pray that by the destruction of the tyranny of sin all
souls may subject themselves to the reign of his holy love. Good Jesus!
for your mercy's sake, hear me in this above all other petitions: never
suffer me to be separated from you by forfeiting your holy love: may I
remain always _rooted and grounded in your charity_, as is the will of
your Father. Eph. iii.

Footnotes:
1. Chron. and Hist., l. 3, c. 30.
2. Hom. 6, in Luc.
3. In Catal. c. 1.
4. Ep. 18, t. 2, Conc. p. 1269.
5. Conc. t. 4, p. 1262.
6. Ep. 40, l. 7, t. 2, p. 888, Ed. Ben.
7. Some have imagined that the feast of the chair of St. Peter was not
known, at least in Africa, because it occurs not in the ancient
calendar of Carthage. But how should the eighth day before the
calends of March now appear in it, since the part is lost from the
fourteenth before the calends of March to the eleventh before the
calends of May? Hence St. Pontius, deacon and martyr, on the eighth
before the Ides of March; St. Donatus, and some other African
martyrs are not there found. At least it is certain that it was kept
at Rome long before that time. St. Leo preached a sermon on St.
Peter's chair, (Serm. 100, t. 1, p. 285, ad. Rom.) Quesnel denied it
to be genuine in his first edition; but in the second at Lyons, to
1700, he corrected this mistake, and proved this sermon to be St.
Leo's; which is more fully demonstrated by Cacciari in his late
Roman edition of St. Leo's works, t. 1, p. 285.
8. Can. 22.
9. Ad an. 566.
10. St. Leo Serm. 100, in Cathedra S. Petri, t. 1, p. 285, ed. Romanae.