When was the pope system introduced?

Answer 1

Jesus Christ appointed Peter as the first leader of his Church when He said:

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 I will give to thee 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 upon earth, it shall be loosed also in heaven. (Matthew Chapt. 16)

Peter is considered the first pope even though the term 'pope' did not come into common usage until much later. Whether Peter was in Jerusalem, Antioch, Rome or elsewhere, he is still considered the first pope. Later, as the Church grew and a hierarchy developed. the Church established its headquarters in Rome as Rome was considered the center of the world at the time. It had good roads reaching out to the vast empire as well as ships that plied the Mediterranean. Missionaries could reach anywhere in the known world from Rome. As the pope was the highest ranking Church authority in Rome, he was automatically consider the Bishop of Rome.

From 1309 until 1377 popes reigned from Avignon in France. No matter, the pope was still the pope. Once the situation was resolved, the papacy returned to Rome and the pope again resumed his position as the Bishop of Rome along with his title of Pope.

Even today, should Pope Francis make the unlikely decision to move the Church headquarters to, say, Buenos Aires, Argentina, he would still be Pope and the assigned Bishop of Rome would simply be the Bishop of Rome. The Pope would be the Bishop of Buenos Aires as well as pope of the Universal Church. The Church has ample evidence that Peter did rule from Rome at some time. But even if he had never stepped foot in the city, he was still the Pope. Being Bishop of Rome is not a prerequisite for the papacy. By default, if the pope is headquartered in Rome, he is also the bishop of that diocese.

And, yes, Peter did reside, at least for a time, in Rome and died there under orders from Roman Emperor Nero. Francis A. Sullivan SJ in his book From Apostles to Bishops states unequivocally that Peter was in Rome and died there. His statement is based on both scripture as well as the writings of early Church fathers. Peter would have assumed leadership about the year AD33 and he died sometime between AD64 and AD67.