This post is not a criticism of the Church or the Pope, God forbid, only the verification of a historical fact.
In the year 330 the emperor Constantine I the Great moves the capital of the Roman Empire to Byzantium – renamed Constantinople -, which after the split will become the capital of the Eastern Roman Empire.
Rome , the eternal capital of the Empire, is orphaned from the earthly power but not from the spiritual one assumed by the bishop of Rome, Silvestre . This self-proclamation and recognition of Rome as the seat of the papacy had to be based on "solid" arguments so that no one could question it. So, let's get to work.
In the Gospel according to Saint Matthew (ch. 16):
And when Jesus came to the parts of Caesarea Philippi, he asked his disciples, saying, Who do men say that the Son of Man is?
And they said, Some, John the Baptist; and others, Elijah; and others; Jeremiah, or one of the prophets.
He said to them:And you, who do you say that I am?
And Simon Peter answered and said:You are the Christ, the Son of the living God.
Then, answering Jesus, he said to him:Blessed are you, Simon, son of Jonas; for flesh and blood did not reveal it to you, but my Father who is in heaven.
But I also tell you, that you are Peter, and on this rock I will build my church; and the gates of hell will not prevail against it.
This would designate Peter as the first Pope, and Sylvester cleverly places Peter at some point in Rome to show that the "capital" of Christianity should be Rome. There is no proof of Peter's stay in Rome... but there is also no proof that he was not there (weak argument or lie?).
Knowing that this argument was a bit strange, they looked for an argument that left no room for doubt and they pulled a document out of their sleeve:
Donation of Constantine :according to this document, Pope Silvester I was recognized as sovereign, the city of Rome was donated to him, as well as the provinces of Italy and all the rest of the Western Roman Empire
In the year 1440 the humanist Lorenzo Valla discovered that the document was totally false. By then, the power of the Pope was so established that no one dared question it.