The story
The birth of Jesus at Bethlehem, in a stable because there was no room at the inn, announced to shepherds by angels and visited by magi from the east who followed a star. The Gospels of Matthew and Luke tell it; the date was fixed in Rome in the fourth century, near the winter solstice and the old festival of the unconquered Sun.
Around the feast the north of Europe wrapped its midwinter: the evergreen tree from Germany, the Yule log, holly and mistletoe, carols from the Middle Ages, and Saint Nicholas of Myra, who became Father Christmas and Santa Claus by way of the Dutch of New York.
In India the day is Baṛā Din, the big day, a public holiday everywhere; Goa, Kerala, Mumbai's Bandra and the north-east keep it with midnight mass, star lanterns at every door, and the crib (nativity scene) in the house.
