III. On the dispersing of the Twelve, St. Peter was sent to Rome
For when the twelve Apostles, after receiving through the Holy Ghost the power of speaking with all tongues, had distributed the world into parts among themselves, and undertaken to instruct it in the Gospel, the most blessed Peter, chief of the Apostolic band, was appointed to the citadel of the Roman empire, that the light of Truth which was being displayed for the salvation of all the nations, might spread itself more effectively throughout the body of the world from the head itself. What nation had not representatives then living in this city; or what peoples did not know what Rome had learned? Here it was that the tenets of philosophy must be crushed, here that the follies of earthly wisdom must be dispelled, here that the cult of demons must be refuted, here that the blasphemy of all idolatries must be rooted out, here where the most persistent superstition had gathered together all the various errors which had anywhere been devised.
Source: Sermons (New Advent)