Why was Jesus born in Bethlehem?

Jesus’ birth in Bethlehem fulfilled the prophecy of Micah.

"But thou, Bethlehem Ephratah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting." - Micah 5:2 KJV

Jesus was born King of the Jews. Wise men saw His star and searched for Him.

"Now when Jesus was born in Bethlehem of Judaea in the days of Herod the king, behold, there came wise men from the east to Jerusalem, Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him." - Matthew 2:1-2 KJV

Perhaps the wise men were searching for the star spoken of by the Gentile prophet Balaam.

"I shall see him, but not now: I shall behold him, but not nigh: there shall come a Star out of Jacob, and a Sceptre shall rise out of Israel..." - Numbers 24:17 KJV

Isaiah prophesied of the visitation of the wise men (kings).

"And the Gentiles shall come to thy light, and kings to the brightness of thy rising." - Isaiah 60:3 KJV

Isaiah foretold of the birth of Christ. He confirmed what Micah foretold, that the ruler “whose goings forth have been from of old, from everlasting” would rule Israel. Isaiah said the child that would be born to rule on the throne of David was the everlasting Father, The mighty God.

"For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace. Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this." - Isaiah 9:6-7 KJV