Final answer:
Luke 2:1 mentions that Caesar Augustus decreed a census of the entire Roman world, leading to Joseph and Mary's journey to Bethlehem.
Step-by-step explanation:
According to Luke 2:1 in the Bible, Caesar Augustus decreed that a census should be taken of the entire Roman world. This was the first census that took place while Quirinius was governor of Syria, and everyone went to their own town to register. The decree by Augustus was an important historical event as it led to Joseph and Mary traveling to Bethlehem, which is where Jesus was born, fulfilling the prophecy of the Messiah's birthplace.