Apart from a handful of references in the synoptic Gospels, the main sources for the life of James the Just are the Acts of the Apostles, the Pauline epistles, Eusebius and Jerome, who also quote the early Christian chronicler Hegesippus and Epiphanius.
Jerome believed that the "brothers" of the Lord were Jesus' cousins, thus amplifying the doctrine of perpetual virginity.
These two works of Hippolytus are often neglected because the manuscripts were lost during most of the church age and then found in Greece in the 19th century.
As most scholars consider them spurious, they are often ascribed to Pseudo-Hippolytus.
Eusebius records that Clement of Alexandria related, "This James, whom the people of old called the Just because of his outstanding virtue, was the first, as the record tells us, to be elected to the episcopal throne of the Jerusalem church." The New Testament mentions several people named James.