James the Just
The Jerusalem Church was an early Christian community located in Jerusalem, of which James the Just, the brother of Jesus, and Peter were leaders. Paul was in contact with this community. Legitimised by Jesus' appearance, Peter was the first leader of the Jerusalem "ekklēsia". He was soon eclipsed in this leadership by James the Just, "the Brother of the Lord," which may explain why the early texts contain scarce information about Peter. According to Lüdemann, in the discussions about the strictness of adherence to the Jewish Law, 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.