Luke probably came from Antioch, was a Pagan Christian and, according to tradition, a doctor by profession (Colossians 4:14) – in the 2nd century he is also called a lawyer; he lived in Boeotia, the land around Thebes – today’s Thiva in Greece. Nothing is known about his conversion to Christianity. Luke therefore joined Paul in (Alexandria) Troas – today ruins at Dalyan – and accompanied him as a companion and faithful friend on his second and third journeys, on the journey to Rome and during captivity there (Phlilemon 24; 2 Timothy 4:11). Since the 2nd century, this Luke has been regarded as the author of the Gospel of the same name and as the author of the Acts of the Apostles, as was the case with Irenaeus of Lyon. Today, the years between 70 and 80 are generally regarded as their time of origin.
Joachim Schäfer: Article Lukas, from the Ecumenical Dictionary of Saints – https://www.heiligenlexikon.de/BiographienL/Lukas.html