Christmas at the Vatican did not always include a giant tree erected in the middle of St. Peter's Square. It took a Polish pope to introduce the custom, which is now an annual Vatican tradition.
St. John Paul II loved Christmas, especially all the traditions that came from his native land of Poland. A friend of John Paul II explains in the book Stories About Saint John Paul II by Wlodzimierz Redzioch that "The Holy Father was very anxious for us to celebrate the holidays in a family atmosphere, according to the Polish traditions ... The Holy Father liked the Christmas tree very much."
Only recently have Italians embraced the Christmas tree tradition, as before the 20th century it was chiefly a tradition of the northern European countries. This is why it took a Polish pope to introduce the tradition at the Vatican.
The traditions also helped connect him in solidarity to his native Poland, which was under martial law from 1981-1983. In 1981 he adopted the custom of placing a candle in his window during the Advent and Christmas seasons to signify his closeness to the Polish people under oppression in his native land.
Later on in 1999 John Paul II explained the symbolism of the Christmas tree in an address to pilgrims from the Czech Republic.
He expressed his fondness for trees in an address in 2000 and how he enjoys seeing it from his window.
In 2004, John Paul II recalled the symbolism of the Christmas tree as a sign of eternal life.
Nearly 40 years later, the Christmas tree continues to be a powerful image in St. Peter's Square, all due to a homesick pope, wanting to celebrate Christmas as he did back home.