St. James the Greater
The Acts of the Apostles also records (12:2) that James was the first martyr among the apostles.
Since there were two with the name "James" among the Twelve Apostles, it's easy to get them both mixed up. One of them is mentioned in Mark 15:40 as "James the less," but this diminutive title most likely refers to his age or height, not his relative importance. So in contrast, the saint commemorated today, the other James, the son of Zebedee and brother of John, is often called "the greater," but again, that flattering title probably just reflects his greater age or height in comparison to the other James.
This St. James and his brother John and St. Peter were privileged to be the closest companions of Jesus among all the apostles, for the three of them are mentioned as alone with the Lord on a number of occasions, including the raising of Jairus' daughter, the Transfiguration, and the Agony in Gethsemane.
The Acts of the Apostles also records (12:2) that James was the first martyr among the apostles. He was put to death by Herod Agrippa I, and since that monarch had a short reign, the year of James' martyrdom is well established as 42 AD.