Barnabas the Cyprian, also called Joseph the Levite, ordained apostle to the Gentiles with Paul, wrote one Epistle, valuable for the edification of the church, which is reckoned among the apocryphal writings. He afterwards separated from Paul on account of John, a disciple also called Mark, none the less exercised the work laid upon him of preaching the Gospel.
Source: De Viris Illustribus (Illustrious Men) (New Advent)