Center for Evangelists

All those even vaguely familiar with Luke’s Christmas story have heard of Caesar Augustus and his famous decree. It was this decree that sent Mary in the ninth month of her pregnancy 80 miles south to Bethlehem, along with husband Joseph.
Caesar Augustus reigned as emperor of the Roman empire from 27 B.C. to 14 A.D. 41 years in all. His decree had two purposes, for an accurate census and to determine taxation.
Caesar Augustus’s reign was marked by peace and security.
Augustus was very interested in the number of citizens in his empire; he was especially interested in whether that number was growing.
Augustus was so concerned about the declining marriage and birth rate in his empire, that he passed legislation that made promiscuity a crime, which penalized bachelors in their right to inherit, and which bestowed political advantages on fathers of three or more children. Because of his demonstrated concern about marriage and birth rate in his empire, it is likely that one of the reasons that Augustus authorized the censuses was to see whether his legislation was working, or, at the very least, to see if the birth rates increased.
Each Citizen had to return to the place of their birth fulfilling God’s prophecy that The Messiah would be born in Bethlehem.

Luke 2:1
And it came to pass in those days, that there went out a decree from Caesar Augustus, that all the world should be taxed.