This caused the beginning of the period of interaction between the popes, the Roman, and the Byzantine emperors. Controversies over historical events Martyrdom of Peter and Paul in Rome Some historians have argued that Peter never in fact went to Rome. This thesis was most prominently advocated by Ferdinand Christian Baur of the Tübingen School. Others, such as Heinrich Dressel in 1872, stated that Peter would have been buried in Alexandria, Egypt, or Antioch, arguing that the notion that Peter founded the church of Rome cannot be traced back before the third century. However, Clement of Rome wrote in a letter to the Corinthians, c. 96 about the persecution of Christians in Rome, reporting that the apostles Peter and Paul were martyred in the imperial capital. St. Ignatius of Antioch wrote soon after Clement, from the city of Smyrna, and in his letter to the Romans, reported that they were to lead it as Peter and Paul did. Between the years 166 and 176, the bishop of Corinth, Dionysius, reported that Paul and Peter preached the Gospel in Rome. Later the writings of Irenaeus, from around 180 AD, indicate a strong belief that Peter "founded and organized" the Church in Rome. Given this and other evidence, many scholars conclude that Peter was indeed martyred in Rome during the reign of Nero. Lutheran historian Adolf von Harnack stated that the previous mainly Protestant theses were biased and that they undermined the study on St. Peter's life in Rome. Episcopal Organization of Rome Initially, the terms "presbyters" and "bishops" were used for the same people, who acted as leaders of the local church, being subject to an apostle. Thus, many historians argue that in the late 1st century, and until the mid 2nd century, the Roman Church did not have a single bishop as head of the local church, but rather had a collegiate form of pastoral leadership; the men who are listed as Peter's immediate successors were possibly prominent individuals in the Roman community, but not single bishops, and that therefore, originally, papal ministry did not exist. However, other scholars and historians disagree, arguing that the apostles designated their successors in leading local churches, which originally were also considered "apostles", citing for example Paul of Tarsus' pastoral charge to Titus and Timothy in the Acts of the Apostles. But by the end of the 1st century this title was reserved for