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Peter was considered along with James the Just and John the Apostle as pillars of the Church. Legitimised by Jesus' appearance, Peter assumed leadership of the group of early followers, forming the Jerusalem "ekklēsia" mentioned by Paul. He was soon eclipsed in this leadership by James the Just, "the Brother of the Lord." According to Lüdemann, this was due to the discussions about the strictness of adherence to the Jewish Law, when the more conservative faction of James the Just took the overhand over the more liberal position of Peter, who soon lost influence. According to Dunn, this was not an "usurpation of power", but a consequence of Peter's involvement in missionary activities. The early Church historian Eusebius (c. AD 325) records Clement of Alexandria (c. AD 190) as saying: