December 25th is the celebration of Jesus Christ birth. Historically, his date of birth is not known but a few indications found in the bible help setting the date on December 25th. Indeed, in the bible, Jesus’ birth coincides with the “rise of the Sun of Justice”. It just so happened that since year 1 BCE, Romans used to celebrate winter solstice, that is to say the birth of Mithra, god of light and justice, who appeared from a rock or a cave in the form of a new born. During his reign, Emperor Constantin the Great decided to make both celebrations fall on the same day. Pope Liberius made it official in Christianity in 354 BCE.