Bartholomew was one of the Twelve Apostles, named in each of the synoptic lists of the apostles and in the Acts of the Apostles. From the patristic period he has widely been identified with Nathanael, the man of Cana in Galilee whom Philip brought to Christ in the Gospel of John; teachers including John Chrysostom, Cyril of Alexandria, and Epiphanius of Cyprus regarded the two names as belonging to a single person. The identification rests on circumstantial grounds: the name Bartholomew, an Aramaic patronymic meaning 'son of Tolmai,' appears in the synoptic Gospels but not in John, while Nathanael appears only in John, and the apostolic lists consistently pair Bartholomew with Philip, who in John is the friend that brings Nathanael to Jesus.
After Pentecost, by tradition, Bartholomew received by lot the task of preaching the Gospel together with the Apostle Philip across Syria and Asia Minor, and Philip's sister Mariamne is said to have accompanied them. Later accounts trace his apostolic labors more widely still, through Phrygia, Lycaonia, Mesopotamia, and the lands bordering the Black Sea, and above all to India and to Greater Armenia. According to a tradition reported by the early Church historian Eusebius, the catechist Pantaenus, on reaching India, found there a copy of the Gospel of Matthew in Hebrew that Bartholomew was said to have left behind among the converts.
The most widespread tradition places the close of his life in Armenia, where he is said to have converted the local king and, in consequence, to have suffered martyrdom under the king's brother or successor. The accounts of his death vary: he is variously said to have been flayed alive, crucified head downward, and beheaded. The motif of flaying became fixed in Christian art, where Bartholomew is most often shown holding his own skin and the knife. The Orthodox synaxarion relates that he was crucified upside down and then flayed and beheaded.
After his martyrdom his relics were venerated and moved repeatedly. By tradition they passed from the place of his death to Dara, and were afterward carried across the Black Sea to the island of Lipari, off Sicily; the return of his relics to Lipari is commemorated on August 25. From Lipari they were translated to Benevento in southern Italy, where a large portion is kept in the basilica that bears his name, and a further portion was given in the tenth century to Rome, where it rests in the church of San Bartolomeo all'Isola.