"The Gospel According to Luke, commonly shortened to the Gospel of Luke or simply Luke, is the third and longest of the four canonical Gospels. It tells of the origins, birth, ministry, death, resurrection and ascension of Jesus Christ," according to Wikipedia.
"Luke and Acts of the Apostles make up a two-volume work from the same pen, called Luke–Acts. The cornerstone of Luke-Acts' theology is 'salvation history', the author's understanding that God's purpose is seen in the way he has acted, and will continue to act, in history.
"It divides history into three stages: first the arrival among men of Jesus the Messiah, from his birth to the beginning of his earthly mission in the meeting with John the Baptist; second the earthly career of Jesus, ending in his Passion, death and resurrection (concluding the gospel story per se); and finally the time of the Church from Peter to Paul, from Jerusalem to Rome (the story told in Acts)."