Smith's Bible Dictionary
(gift of God). A disciple of Jesus Christ, concerning
whom, under that name at least, we learn from Scripture little more than
his birthplace, Cana of Galilee,
Joh_21:2, and his simple, truthful character.
The name does not occur in the first three Gospels, but it is commonly
believed that Nathanael and Bartholomew are the same person.
The evidence for that belief is as follows: St. John, who twice mentions Nathanael, never introduces the name of Bartholomew at all. St. Matthew,Mat_10:3, St. Mark, Mar_3:18, and St. Luke, Luk_8:14, all speak of Bartholomew, but never of Nathanael. If was Philip who first brought Nathanael to Jesus, just as Andrew had brought his brother, Simon.
Barthol'omew. (son of Tolmai). One of the twelve apostles of Christ.Mat_10:3; Mar_3:18; Luk_6:14; Act_1:13. It has been not improperly conjectured that, he is identical with Nathanael. Joh_1:45. ff. He is said to have preached the gospel in India, that is, probably, Arabia Felix, and according to some in Armenia.
Taken from: Smith's Bible Dictionary by Dr. William Smith (1884)