James, Son of Alphaeus

Concise Bible Dictionary:

One of the twelve apostles (Matt. 10:3; Mark 3:18; Luke 6:15; Acts 1:13). These are the only passages where with certainty this apostle is spoken of; but we find in the Acts of the Apostles a James at Jerusalem after the son of Zebedee had been killed, and holding a sort of first place there. He spoke with a measure of authority at the conference respecting the law not being enforced on the Gentiles, saying, “My sentence is ... ” This suggests that he was an apostle, and the son of Alphaeus (Acts 12:17; Acts 15:13; Acts 21:18; Gal. 2:9,12). He was most probably the writer of the Epistle of James, and the brother of Jude, or Judas, who was also an apostle (Luke 6:16; James 1:1; Jude 1).