So Ireneaus, who was a bishop in the second century, is the one who attributed names to the gospels, since they were all written anonymously. He’s the one who said that what we now know as the Gospel of Luke (gLuke) and Acts were written by Luke, “a traveling physician” and a friend of Paul of Tarsus. But who was Luke?
Not much is known about him, except that Paul writes that he’s a physician who’s “with him” in 2 Timothy 2:14 and Colossians 4:14. Those are the only times that Paul references a “Luke”.