The Confession of Peter ("Thou art the Christ, the Son of the Living God") is commemorated on 18 January, and the Conversion of Paul (on the approach to Damascus) a week later on 25 January. On 29 June we commemorate the martyrdoms of both apostles. The date is the anniversary of a day around 258, under the Valerian persecution, when what were believed to be the remains of the two apostles were both moved temporarily to prevent them from falling into the hands of the persecutors.
The Scriptures do not record the deaths of Peter or Paul, or indeed any of the Apostles except for James the son of Zebedee (Acts 12:2), but they are clearly anticipated (see the readings below), and from an early date it has been said that they were martyred at Rome at the command of the Emperor Nero, and buried there. As a Roman citizen, Paul would probably have been beheaded with a sword. It is said of Peter that he was crucified head downward. The present Church of St Peter in Rome replaces earlier churches built on the same site going back to the time of the Emperor Constantine, in whose reign a church was built there on what was believed to be the burial site of Peter. Excavations under the church suggest that the belief is older than Constantine.
St. Augustine writes (Sermon 295):
Both apostles share the same feast day, for these two were one; and even though they suffered on different days, they were as one. Peter went first, and Paul followed. And so we celebrate this day made holy for us by the apostles' blood. Let us embrace what they believed, their life, their labors, their sufferings, their preaching, and their confession of faith.
FIRST READING: Ezekiel 34:11-16
(The LORD God will be a shepherd to Israel, and they shall be His flock.)
(The foundations of Zion, the city of God, rest upon the holy hills. Of many nations it shall be said: In Zion were they born.)
EPISTLE: 2 Timothy 4:1-8
(Paul writes: "I am now ready to be offered, and the time of my departure is at hand. I have fought a good fight, I have finished the course, I have kept the faith.")
THE HOLY GOSPEL: John 21:15-19
(Jesus, after rising from the dead, said to Peter: "When you were young, you went where you would, but when you are old, you will go where you are taken." And by these words, He foretold Peter's death. He then said, "Follow me.")
Almighty God, whose blessed apostles Peter and Paul glorified thee by their martyrdom: Grant that thy Church, instructed by their teaching and example, and knit together in unity by thy Spirit, may ever stand firm upon the one foundation, which is Jesus Christ our Lord; who liveth and reigneth with thee, in the unity of the same Spirit, one God, for ever and ever.