Because the Western church so often identified James the son of Alphaeus with James the Just, the brother of the Lord and first leader of the Jerusalem community, much of what is said about the apostle is really borrowed from that far better-attested figure. James the Just is described by the Jewish historian Josephus, who reports his execution in Jerusalem around the year 62 on the order of the high priest Ananus, and by later Christian writers who made him a model of ascetic piety, called the Just and, in one tradition, thrown from the pinnacle of the Temple.
Where the son of Alphaeus is treated as a distinct man, the traditions are thin and divergent, sending him to preach in various regions and giving him a martyr's death, often by being clubbed or sawn, with little that is early or firm behind it.
In the Western liturgical calendar he is commemorated together with the apostle Philip, and iconography sometimes gives him a fuller's club as the instrument of his death, an attribute inherited, once again, from the story of James the Just. The one certainty is the least satisfying: a name on the roll of the twelve, and behind it a man about whom the sources genuinely disagree even as to who he was.