Census of Quirinius
The Census of Quirinius was a census of Judea taken by Publius Sulpicius Quirinius, Roman governor of Syria, upon the imposition of direct Roman rule in 6 CE. The Gospel of Luke uses it as the narrative means to establish the birth of Jesus in Bethlehem (Luke 2, Luke 2:1–5), but the Gospel of Matthew places the birth within the reign of Herod the Great, who had died 9 years earlier. No satisfactory explanation of the contradiction seems possible, and most critical scholars think that the Gospel of Luke was in error.
In 6 CE the Roman Empire deposed Herod Archelaus, who ruled the largest section of Judea as a Roman client king, and converted his territory into the Roman province of Judea, and Publius Sulpicius Quirinius, the legatus (governor) of the province of Roman Syria was assigned to carry out a census of the new province for tax purposes. The gospel of Luke uses this census to establish the year in which Jesus was born.
In those days a decree went out from Emperor Augustus that all the world should be registered. This was the first registration and was taken while Quirinius was governor of Syria. All went to their own towns to be registered. Joseph also went from the town of Nazareth in Galilee to Judea, to the city of David called Bethlehem, because he was descended from the house and family of David. He went to be registered with Mary, to whom he was engaged and who was expecting a child.
There are major difficulties in accepting Luke's account: the gospel links the birth of Jesus to the reign of Herod the Great, but the census took place in 6 CE, nine years after Herod's death in 4 BCE; there was no single census of the entire empire under Augustus; no Roman census required people to travel from their own homes to those of distant ancestors; and the census of Judea would not have affected Joseph and his family, living in Galilee.
Some conservative scholars have argued that Quirinius may have had an earlier and historically unattested term as governor of Syria, or that he previously held other senior positions which may have led him to be involved in the affairs of Judea during Herod's reign, or that the passage should be interpreted in some other fashion; the English Standard Version, for example, has a footnote which offers "This was the registration before Quirinius was governor of Syria" as an alternate translation, but this is not in the text of any major English translation.
These "exegetical acrobatics" (in the words of Géza Vermes) spring from the assumption that the Bible is inerrant. They have generally been rejected because there is no time in the career of Quirinius before 6 CE when he could have served as governor of Syria, the Romans did not directly tax client kingdoms, and the hostile reaction of the Jews in 6 CE suggests direct taxation by Rome was new at the time. Most critical scholars have therefore concluded that Luke's account is in error.