The Chair of St Peter at Antioch
To honour the dignity of the "prince" (Introit) to whom Jesus has committed the power of the keys (Collect), the Church instituted the feast of the "Chair of St Peter," which is found in the Roman calendar at this date since the year 354.
As it often falls in Lent, certain churches celebrated it at an earlier date, in January. Hence the two feasts of the Chair of St Peter, which the Church distinguished by connecting the more ancient one [Rome, until the sixteenth century, only celebrated this date], on February 22nd, with the Chair at Antioch, and the one on January 18th with the Chair of Peter at Rome. St Peter indeed resided for some time at Antioch about the years 51-52.
It is to St Peter, who proclaimed that Jesus was was "the Christ, Son of the living God" (Gospel) when all Palestine rejected Him that the Master commits the power to bind Satan by closing the gates of hell, to open for us the gates of heaven (Gospel). And the Head of the Church teaches us in his first Epistle that it is "by faith in the sprinkling of the blood of Jesus Christ that the Holy Ghost sanctifies us and reconciles us to the Father."
The commemoration of St. Paul immediately follows the Collect of the feast, for the liturgy does not separate those who have so justly been called the two pillars of the Church.
Let us to-day honour the Head of the Church who continues here below the redeeming work of Jesus.
Statuit ei Dominus testamentum pacis, et principem fecit eum: ut sit illi sacerdotii dignitas in aeternum. * Memento Domine David et omnis mansuetudinis ejus.
The Lord made to him a covenant of peace, and made him a prince; that the dignity of the priesthood should be to him for ever. * O Lord, remember David: and all his meekness.
(Ecclus. 45:30 and Psalm 131:1. From the Introit at Mass).
Deus, qui beato Petro Apóstolo tuo, collátis clavibus regni coeléstis, ligandi atque solvéndi pontifícium tradidísti: concéde; ut, intercessiónis ejus auxilio, a peccatorum nostrórum néxibus liberémur.
O God, Who, committing to blessed Peter, Thine apostle, the keys of the heavenly kingdom, didst bestow on him the pontifical function of binding and loosing, grant that, by the help of his intercession, we may be delivered from the bonds of our sins.
Deus, qui multitúdinem géntium beati Pauli Apóstoli praedicatióne docuisti: da nobis, quaesumus: ut cujus commemoratiónem colimus, ejus apud te patrocínia sentiámus.
O God, Who by the preaching of the blessed apostle Paul didst teach the multitude of the gentiles, grant us, we pray Thee, that, honoring his commemoration, we may experience the benefit of his patronal influence with Thee.
(Commemoration of St Paul)
The continuation of the holy Gospel according to Matthew.
At that time, Jesus came into the quarters of Caesarea Philippi, and He asked His disciples, Saying, "Whom do men say that the Son of man is?" But they said, Some, John the Baptist, and other some, Elias, and others, Jeremias, or one of the prophets. Jesus saith to them,"But whom do you say that I am?" Simon Peter answered, Thou art Christ, the Son of the living God. And Jesus answering, said to him,"Blessed art thou, Simon Bar Jona, because flesh and blood hath not revealed it to thee, but My Father Who is in Heaven: and I say to thee, that thou art Peter, and upon this rock I will build My Church, and the gates of hell shall not prevail against it; and to thee I will give the keys of the kingdom of Heaven; and whatsoever thou shalt bind upon earth, it shall be bound also in Heaven; and whatsoever thou shalt loose on earth, it shall be loosed also in Heaven."
(St Matthew 16:13-19)
Tu es Petrus, et super hanc petram aedificabo Ecclésiam Meam: et portae ínferi non praevalébunt advérsus eam: et tibi dabo claves regni coelórum.
Thou art Peter, and upon this rock I will build My Church, and the gates of hell shall not prevail against it; and I will give to thee the keys of the kingdom of Heaven.
(St Matthew 16:18-19)
From the Catholic Encyclopaedia on the Chair of St Peter: http://www.newadvent.org/cathen/03551e.htm