St. Luke is the author of the third Gospel (in the order of the Vulgate) and the Acts of the Apostles. He was born in Antioch, Syria (as reported by saints Eusebius and Jerome) and died in Thebes in 93 ca. He was a physician (Col. 4:14).
In 49 or 50 A.D. he accompanied St. Paul in some of his missionary journeys and he later witnessed the apostle's arrest and incarceration (Acts 21:18, 26:32 ). When Paul was transferred from Caesarea to Rome, Luke accompanied him (Acts 27:22 , 8:29.)
The Gospel of St. Luke was written after those of Mark and Matthew and prior to the book of the Acts of the Apostles (ca. 63). Its preparation seems to date back to the years 60-63, while he was probably in Rome, or in Caesarea.
Luke's Gospel was based on solid sources: he consulted written documents and drew from facts transmitted orally. Luke drew, at least indirectly, in the treasury of memories of Mary (Luke 2:19 and 2:51 ). He had the opportunity to receive valuable information from Saint John's surroundings ( Luke 9:54 ), by Peter (Luke 22:8 ), by Cleophas (Luke 00:18 ), and by the deacon Philip (Acts 21:8 ). The pious women Mary and Martha (Luke 10:38) could inform him of episodes that regarded them directly. Manahen, the childhood friend of Herod ( Acts 13:1 ), probably told him about the appearance of Jesus before the tetrarch
(Luke 23:7-12 ).
An ancient Christian tradition maintains that Luke was the first iconographer as he painted images of the Virgin Mary, Peter and Paul. There are many Byzantine images attributed to him. The portraits by Luke would have been preserved for centuries in Rome and Jerusalem, paving the way to a proper school of religious icons.
Luke pointed out in the prologue of his Gospel that he was very careful in collecting information from "eyewitnesses" (1:1-4). The Mother of Jesus was possibly one of these eyewitnesses. In fact, the Gospel of Luke is the only historical record providing accurate information on the Virgin and on the childhood of Jesus.
On the other hand, Luke's role as a doctor suggested a familiarity with his activity as a painter, which in the tradition of late antiquity was considered indispensable tool for illustrating repertoires of medicinal plants and bodies. At the same artists were always required expertise in the field of botanic for the packaging of colors.
Source: the Catholic Encyclopedia; Cathopedia.