Early Christian Roots. Throughout the early Christian era, the Church of Rome grew in importance within the Church at large. Because the apostle Peter had been martyred in Rome, the bishops of Rome, or popes, were seen as his successors. Even though the bishop of Rome was nominally the equal of any other bishop, a belief in the primacy of the bishop of Rome began to develop as early as the third century, when the North African Church Father Tertullian wrote of "Rome, from which there comes . . . the very authority of the apostles themselves." Pope Leo I (reigned 440-461) became the first systematizer of papal primacy, interpreting older statements about the papal role in the Church by means of the principles of Roman law, according to which all the rights and duties of the deceased were transferred to the...