meaning, as agreed by representatives of both the Catholic and the Eastern Orthodox Churches, that "Rome, as the Church that 'presides in love' according to the phrase of St Ignatius of Antioch (To the Romans, Prologue), occupied the first place in the taxis, and that the bishop of Rome was therefore the protos among the patriarchs". The same agreement stated: Basis of claims to primacy Peter and Paul The evolution of earlier tradition established both Peter and Paul as the forefathers of the bishops of Rome, from whom they received their position as chief shepherd (Peter) and supreme authority on doctrine (Paul). To establish her primacy among the churches of the Western half of the empire, the bishops of Rome relied on a letter written in 416 by Innocent I to the Bishop of Gubbio, to show how subordination to Rome had been established. Since Peter was the only apostle (no mention of Paul) to have worked in the West, thus the only persons to have established churches in Italy, Spain, Gaul, Sicily, Africa, and the Western islands were bishops appointed by Peter or his successors. This being the case then, all congregations had to abide by the regulations set in Rome. Primacy of Peter the apostle Because of its association with the supposed position of Peter among the apostles, the function that, within the Catholic Church, is exercised by the Bishop of Rome among the bishops as a whole is referred to as the Petrine function, and is generally believed to be of divine institution, in the sense that the historical and sociological factors that influenced its development are seen as guided by the Holy Spirit. Not all Catholic theologians see a special providential providence as responsible for the result, but most see the papacy, regardless of its origin, as now essential to the Church's structure. The presence of Peter in Rome, not explicitly affirmed in, but consistent with, the New Testament, is explicitly affirmed by Clement of Rome, Ignatius of Antioch, Irenaeus of Lyon and other early Christian writers – and no other place has ever claimed to be the location of his death. The same witnesses imply that Peter was the virtual founder of the Church of Rome, though not its founder in the sense of initiating a Christian community there. They also speak of Peter as the one who initiated its episcopal succession, but speak of