It is during the great forty days that our Lord founded the Primacy, when He made S. John and the rest of the Apostles sheep of Peter's fold. The period of thirty-eight years which follows is the carrying into effect His design in the first stage. The Church grows around Peter. First in Jerusalem he forms a mass of disciples; then for a certain number of years at Antioch. In the second year of Claudius, the thirteenth after the Ascension, he lays the foundations of the Roman Church. In the sixtieth year of our era he sends forth S. Mark to found the Christian society in Alexandria. Thus he takes possession of the three great cities of the empire, of east, west, and south. In the mean time the labours of S. Paul and the other Apostles, in conjunction with those of Peter and in subordination to them, plant the Christian root in a great number of cities. As S. Paul toils all round the northern circuit of the empire, through Asia Minor, Macedonia, Illyricum, to Spain, his work has a manifest reference to the work of Peter in the metropolis of the east, of the south, and of the west. In the latter he joins his elder brother, and the two Princes of the Apostles offer up their lives together on the same day in that city which was to be the perpetual citadel of the Christian Faith, the immovable Rock of a divine Capitol. Thus was it Peter, "from whom the very Episcopate, and all the authority of this title sprung,"(292) and what Pope Boniface wrote in 422 is a simple fact of history: that "the formation of the universal Church at its birth took its beginning from the honour of blessed Peter, in whose person its regimen and sum consists. For from his fountain the stream of ecclesiastical discipline flowed forth into all churches, as the culture of religion progressively advanced."(293) Thus the whole initial movement was from above downwards, and S. Cyprian was not only enunciating dogma but speaking history when he wrote that the Lord built the Church upon Peter. In one generation the structure rose above the ground, and during all that time S. Peter's hand directed the work.
Just at the end of this time, on the point of being thrown into prison, whence he only emerged to martyrdom, Paul was at Rome with Peter, and he describes in imperishable words the work which had been already accomplished. Again it is not only dogma but history, not only that which was always to be but that which already was, which he set forth as it were with his dying voice: the one Body, and the one Spirit, the one Lord, one Faith, and one Baptism, as there is one God. That Body in which Apostles, Prophets, Evangelists, Pastors and Teachers were fixed, that the visible structure might grow up to its final stature, in whose accordant unity was the perpetual safeguard against error. When Paul so wrote,(294) the Body was formed, and its headship was incontestably with Peter. He had no need to remind them of the man with whom he was labouring, of whose work the whole Church from Rome to Antioch and Alexandria was the fruit. But he places the maintenance of truth, and the perpetual fountain of grace, in the unity of the Church, which was before those to whom he wrote an accomplished fact.