Jesus had several brothers mentioned in the New Testament, specifically named as James, Joseph (also called Joses), Simon, and Judas (Jude). These names appear in Mark 6:3 and Matthew 13:55, which also mention that Jesus had sisters, though their names and number are not specified

. Among these brothers, James is the most prominent. He is often called James the Just and became a leading figure in the early Christian church in Jerusalem. He was known for his devoutness and leadership, eventually serving as the bishop of Jerusalem. Historical sources report that James was martyred around 62 AD

. The exact nature of Jesus' brothers has been debated. The most straightforward reading of the biblical texts suggests they were Jesus' literal half-brothers, children of Mary and Joseph after Jesus' birth. This is supported by the use of the Greek word "adelphoi," which typically means biological brothers. Some Christian traditions, particularly Catholic and Orthodox, argue that these brothers were actually cousins or stepbrothers from a previous marriage of Joseph, to uphold the doctrine of Mary's perpetual virginity. However, these interpretations are not directly supported by the biblical text, which consistently refers to them as brothers and sisters

. In summary, Jesus' brothers were James, Joseph, Simon, and Judas, likely his biological half-brothers, with James being the most historically significant among them as a leader in the early church