Catholic Encyclopedia: St. Bartholomew - Mentioned in the lists of apostles in the Synoptic Gospels and in Acts, thought to be identical with Nathaniel (mentioned only in the Gospel of John).
Martyrdom of the Holy and Glorious Apostle Bartholomew - Apocryphal. According to this story, Bartholomew went to "India," where he was beheaded for having converted King Astreges' brother Polymius to Christianity. From the Ante-Nicene Fathers, vol. 8.