Pope Cornelius was the bishop of Rome from 6th or 13th March 251 until his martyrdom in June 253. He was pope during and following a period of persecution of the church, while a schism occurred over how repentant church members who had practiced pagan sacrifices to protect themselves could be readmitted to the church. He agreed with Cyprian of Carthage that those who had lapsed could be restored to communion after varying forms of Reinitiation and Penance. This position was in contrast to the Novatianists, who held that those who failed to maintain their confession of faith under persecution would not be received again into communion with the church. This resulted in a short-lived schism in the Church of Rome that spread as each side sought to gather support. Cornelius held a synod that confirmed his election and excommunicated Novatian, but the controversy regarding lapsed members continued for years.

The pope, also known as the supreme pontiff, Roman pontiff or sovereign pontiff, is the bishop of Rome, visible head of the worldwide Catholic Church, and has also served as the head of state or sovereign of the Papal States and later the Vatican City State since the eighth century. From a Catholic viewpoint, the primacy of the bishop of Rome is largely derived from his role as the apostolic successor to Saint Peter, to whom primacy was conferred by Jesus, who gave Peter the Keys of Heaven and the powers of "binding and loosing", naming him as the "rock" upon which the Church would be built. The current pope is Francis, who was elected on 13 March 2013.