The Synaxis of the Glorious and All-Praiseworthy Twelve Apostles of Christ appears to be an ancient Feast. The Church honours each of the Twelve Apostles on separate dates during the year, and has established a general commemoration for all of them on the day after the commemoration of the Glorious and First-Ranked among the Apostles Peter and Paul.
The holy God-crowned Emperor Constantine the Great (commemorated May 21) built a church in Constantinople in honour of the Twelve Apostles. There are instructions for celebrating this Feast, which date from the fourth century.
The names of the Twelve Apostles are these: Simon, who was called Peter, and his brother Andrew, the First-called; James the son of Zebedee, and his brother John, who was also the Evangelist and Theologian; Philip, and Bartholomew; Thomas, and Matthew the publican, who was also called Levi and was an Evangelist; James the son of Alphaeus, and Jude (also called Lebbaeus, and surnamed Thaddaeus), the brother of James, the Brother of God; Simon the Cananite ("the Zealot"), and Matthias, who was elected to fill the place of Judas the traitor.