Place of birth

The Gospels of both Matthew and Luke place the birth of Jesus in Bethlehem. The Gospel of Matthew implies that the family already lived in Bethlehem when Jesus was born. According to the Gospel of Luke, Joseph and Mary (who lived in Nazareth) had traveled to Bethlehem to register for the census of Quirinius, because it was the town of Joseph’s ancestors, the birthplace of David.
The Gospel of Luke account states that Mary gave birth to Jesus and laid him in a manger “because there was no place for them in the inn," but does not say exactly where Jesus was born. The Greek word kataluma may be translated as either “inn” or “guestroom”, and some scholars have speculated that Joseph and Mary may have sought to stay with relatives, rather than in an inn, only to find the house full (whereupon they resorted to the shelter of a room with a manger).
Although in Western art the manger is usually depicted as being in a man-made free standing structure, many biblical scholars conjecture that, as in Byzantine art, the manger was probably positioned in a cave carved in the side of a hill. In the second century, Justin Martyr stated that Jesus had been born in a cave outside the town, while the Protoevangelium of James described a legendary birth in a cave nearby. The Church of the Nativity inside the town, built by St. Helena, contains the cave-manger site traditionally venerated as the birthplace of Jesus, which may have originally been a site of the cult of the god Tammuz.
The earliest sources on Jesus's paternity are the letters of Saint Paul, written between about the years 50 and 65. Paul addresses Jesus's paternity only twice. In both cases, he says that Jesus was born "under the Law" (i.e., a Jew, and therefore of a Jewish father), of the line of David (which could only be traced through the male line), but "declared to be the Son of God" through his resurrection from the dead.
The Gospels are all removed by at least a generation from the time of Jesus. Mark, the earliest of them, makes no mention at all of Jesus's father Joseph, but casts doubt on the idea of descent from David: "How can he [the Messiah] be his [David’s] son?’,The famous birth narratives appear only in the later Gospels, those of Matthew and Luke.