The year CE 1, alternately known as 1 AD, is popularly taken to be the birth-year in which Jesus of Nazareth is born, although modern scholarship places the event at about 5 or 4 BCE.

The Gospel of Matthew, in its Nativity account, associates the birth of Jesus with the reign of Herod the Great, who is generally believed to have died around 4 BC/BCE.

Matthew 2:1 states that: "Jesus was born in Bethlehem of Judaea in the days of Herod the king" and Luke 1:5 mentions the reign of Herod shortly before the birth of Jesus.

Matthew also suggests that Jesus may have been as much as two years old at the time of the visit of the Magi and hence even older at the time of Herod's death, but the author of Luke also describes the birth as taking place during the first census of the Roman provinces of Syria and Iudaea, which is generally believed to have occurred in 6 AD/CE.

Most scholars generally assume a date of birth between 6 and 4 BC/BCE.

Other scholars assume that Jesus was born sometime between 7 and 2 BC/BCE.

The year of birth of Jesus has also been estimated in a manner that is independent of the Nativity accounts, by using information in the Gospel of John to work backwards from the statement in Luke 3:23 that Jesus was "about 30 years of age" at the start of his ministry.

By combining information from John 2:13 and John 2:20 with the writings of Flavius Josephus, it has been estimated that around 27-29 AD/CE, Jesus was "about thirty years of age".

Some scholars thus estimate the year 28 AD/CE to be roughly the thirty-second birthday of Jesus and the birth year of Jesus to be around 6-4 BC/BCE.

However, the common Gregorian calendar method for numbering years, in which the current year is 2012, is based on the decision of a monk Dionysius in the sixth century, to count the years from a point of reference (namely, Jesus’ birth) which he placed sometime between 2 BC and 1 AD.

Although Christian feasts related to the Nativity have had specific dates (e.g. December 25 for Christmas) there is no historical evidence for the exact day or month of the birth of Jesus.

Christian tradition, based on the Gospels of Saints Mark, Matthew, Luke, and John, has Mary, his mother, being told by an angel that God had miraculously impregnated her.

She and her husband Joseph reportedly traveled to be counted in a census ordered by Augustus, stopping in the town of Bethlehem, the ancestral city of David, to give birth.

The birth of her son, Jesus, is reportedly accompanied by signs and prophecies pointing to his importance as the fulfillment of the hopes of Israel and of God's redemptive purpose for the world.

Jesus is traditionally considered a descendant of Abraham, the father of the Jewish people, and David, their most illustrious king.

Reportedly present at the birth are three "wise men from the East" who follow a star to Bethlehem to worship the infant Jesus, presenting him with gifts of frankincense, gold, and myrrh.

In a Biblical event paralleling the account in Exodus of Pharaoh's massacre of Jewish male babies at the time of Moses' birth, Herod the Great, who died between 4 and 1 BC, had allegedly tried to kill the infant males of Bethlehem, forcing Mary and Joseph to take Jesus to Egypt for safety.

Although Herod is certainly guilty of many brutal acts, including the killing of his wife and two of his sons, the historical accuracy of this event has been questioned, since no other document from the period makes any reference to such a massacre.

Bethlehem is at this time a small rural town, and the number of male children under the age of two would probably not exceed twenty; the number of children actually killed, if any, may have been as few as five or six.

This may be the reason for the lack of other sources for this history, although Herod's order in Matthew 2:16 includes those children in Bethlehem's vicinity making the massacre larger numerically and geographically.

Modern biographers of Herod tend to doubt the event took place; most recent biographies of Herod the Great deny it entirely. (Paul L. Maier, "Herod and the Infants of Bethlehem", in Chronos, Kairos, Christos II, Mercer University Press [1998], p.170.)