According to tradition, the birth of Jesus Christ was on December 25th. In the early centuries of Christianity, this date was not celebrated as a special day. However, as Christianity spread throughout Europe, it became common to celebrate the birth of Jesus. The day of his birth was chosen as a day of celebration because it was thought to be the day he was born, and because it was close to the winter solstice, which was a time of year that was important to many cultures. The date December 25th became the official date for Christmas in the fourth century AD.