Pope Benedict informally cut the ribbon on his third Christmas as pontiff on Monday by unveiling a new-style Nativity Scene in St Peter's Square.
In a move which is unprecedented in modern times, the Vatican decided to abandon the traditional stable-and-manger scenario this year in order to depict Jesus being born in Joseph's house.
The choice was apparently an attempt to draw attention to St Matthew's version of the Nativity, which makes no mention of the journey to Bethlehem. It simply says that Joseph took Mary into his house and she gave birth there.
The pope recently stressed the importance he attached to Nativity Scenes and Christmas trees in the celebrations organised by the world's 1.1 billion Catholics to mark the Church's most important festivity of the year.
''They are elements of that typical Christmas atmosphere which is part of the spiritual patrimony of our communities,'' he said, adding that they created a climate ''infused with religious feeling and family intimacy''.
The unveiling of the innovative Nativity Scene, the first of Benedict's public appearances over the Christmas holiday, was to be followed by the lighting of a candle for peace at the window of the pope's study.
At his last general audience before Christmas, the pontiff said he was praying for a ''celebration of peace'', adding that the world needed it ''urgently''.
''We ask God that violence be defeated by the force of love, conflicts give way to reconciliation, oppression be transformed into a desire for forgiveness, justice and peace,'' he said.
The 80-year-old pope's Christmas schedule requires him to preside over six ceremonies in two weeks.
The schedule, which contains no breaks with tradition, starts on Monday evening when the pope celebrates Midnight Mass in St Peter's Basilica.
Then at noon on Tuesday, Christmas Day, he delivers his Christmas message and gives the 'urbi et orbi' (to the city of Rome and the world) blessing from the central balcony of St Peter's.
The ceremony and message, which is a central feature of Christmas for Catholics around the world, will be broadcast live to 57 nations via 95 television networks, the Vatican said.
On December 31, at 6 pm, Benedict will preside over Vespers in St Peter's and on January 1 he will take a morning mass marking the 41st World Day of Peace.
Five days later, on January 6, the pontiff will celebrate an Epiphany mass in the morning and then close the Christmas season the next day with a mass in the famous Sistine Chapel.
Away from the public spotlight, the pope's Christmas was expected to be spent quietly with his closest aides and the nuns who look after him in the Apostolic Palace.
Benedict's elder brother, Father Georg, was not expected in the Vatican until the weekend. He told a German news magazine: ''At Christmas my brother is always very busy. He has to work. I'll go to Rome on December 28''.
