The doctrine had the most significance in the relationship between the church and the temporal state, in matters such as ecclesiastic privileges, the actions of monarchs and even successions.
The Catholic doctrine of papal supremacy is based on the assertion by the Bishops of Rome that it was instituted by Christ and that papal succession is traced back to Peter the Apostle in the 1st century. The authority for the position is derived from the Confession of Peter documented in Matthew 16:17–19 when, in response to Peter's acknowledgment of Jesus as the Messiah and Son of God, which many relate to Jesus' divinity, Jesus responded:
Blessed art thou, Simon Bar-Jona. For flesh and blood hast not revealed this to thee, but my Father who is in heaven. And I say to thee, thou art Peter, and upon this rock I will build my church, and the powers of death shall not prevail against it. I will give to thee the keys of the kingdom of heaven, and whatsoever thou shalt bind on earth shall be bound in heaven, and whatsoever thou shalt loose on earth shall be loosed in heaven.
Some scholars as well as critics believe that there was no single “bishop” of Rome until well after the year 150 AD, and that there was no papacy for the first three centuries. Catholic theologian Francis A. Sullivan "expressed agreement with the consensus of scholars that available evidence indicates that the church of Rome was led by a college of presbyters, rather than a single bishop, for at least several decades of the second century." The research of Jesuit historian Klaus Schatz led him to state that, "If one had asked a Christian in the year 100, 200, or even 300 whether the bishop of Rome was the head of all Christians, or whether there was a supreme bishop over all the other bishops and having the last word in questions affecting the whole Church, he or she would certainly have said no." But he believes it likely that 'there very quickly emerged a presider or ‘first among equals.’" Critics argue that, in contrast to a universal papacy to which all were subject, Roman bishops who tried to exert authority as supreme heads were severely reprimanded by other bishops, and that it was not until the 4th and 5th centuries that papal primacy, helped by myths and legends, began to take shape. This marked the beginning of the rise of the Bishops of Rome to the position of not just religious authority, but also of the power to be the ultimate ruler of the kingdoms within the Christian community (Christendom), which it has since retained.
Catholics have countered this argument by the fact that in the first three centuries of Christianity the church in Rome intervened in other communities to help resolve conflicts. Pope Clement I did so in Corinth in the end of the first century. In the end of the 2nd century, Pope Victor I threatened to excommunicate the Eastern bishops who continued to celebrate Easter on 14 Nisan, not on the following Sunday In the third century, Pope Cornelius convened and presided over a synod of 60 African and Eastern bishops, and his rival, the antipope Novatian, claimed to have "assumed the primacy".