James was the son of Zebedee and Salome. Salome was a sister of Mary (mother of Jesus) which made James the Great a cousin of Jesus. James is styled "the Greater" to distinguish him from the Apostle James "the Less," with "greater" meaning older or taller, rather than more important. James the Great was the brother of John the Apostle.
James is described as one of the first disciples to join Jesus. The Synoptic Gospels state that James and John were with their father by the seashore when Jesus called them to follow him.
James, along with his brother John, and Peter, formed an informal triumvirate among the Twelve Apostles. Jesus allowed them to be the only apostles present at three particular occasions during his public ministry, the raising of Jairus' daughter,[4] transfiguration of Jesus[5] and agony in the Garden of Gethsemane
–Wikipedia