4. The missionary zeal of the Roman Church soon led to the formation of a number of suburban branches and within a comparatively short period to the spread of Christianity throughout Italy and to other sections of Western Europe.[152:3] These local churches naturally looked to the head of the Church in the great capital for assistance and instruction, and were willing to acknowledge his jurisdiction and pretensions. The episcopal organisation of the Church in the West, which was probably present from the beginning,[152:4] made the transition to the hierarchy comparatively simple. At Rome the process may be more plainly traced than in connection with any other church. 5. The persecutions of the Christians[152:5] centred in Rome and, consequently, made the Bishop of Rome a conspicuous leader, with social and political, as well as religious duties, whose office was frequently sanctified by martyrdom. The persecutions helped to emphasise the necessity of a better organisation on a monarchio-episcopal basis. That organisation became very exclusive,[153:1] and made a responsible head imperative. Who else but the Bishop of Rome could meet the demands? To him was given, by general consent in the West, the headship of the Church and he began to act as the conscious Pope of Christendom. 6. The Bishop of Rome was the only official organ of communication between the East and West. He was the sole Patriarch of all the united West, while the East had four Patriarchs,[153:2] and the sixth canon of the Council of Nicæa confirmed his jurisdiction as an "ancient custom." From Clement (95), whose writings are the earliest of any Bishop of Rome preserved, onward, he speaks in an authoritative tone, not only to the churches of Carthage, Italy, and Gaul, but also to Greece, Asia Minor, Palestine, and Alexandria. Notwithstanding the fact that Alexandria and Antioch also claimed Peter for their founder, yet not one of the four patriarchates attempted to contest Rome's claim to priority of rank.[153:3]