Pope Benedict XVI will be officially installed Sunday as the leader of the Roman Catholic Church in public ceremonies at the Vatican.

In accordance with centuries-old tradition, the new Church leader will visit the crypt beneath St. Peter's Basilica where St. Peter - the first pope - is said to be buried. There, Benedict will receive the two symbols of his authority - his Fisherman's ring bearing the image of St. Peter, and a pallium - a white wool stole emblazoned with five red crosses.

Next, the new pope will preside over a two-hour ceremony in St. Peter's Square that includes a Mass with portions read in several languages including Arabic, Chinese and German.

Dozens of world and religious leaders and dignitaries, and some 500,000 pilgrims are expected to be in attendance. Among the officials will be German Chancellor Gerhard Schroeder, and President Bush's younger brother, Florida Governor Jeb Bush, who is Catholic.

The former Cardinal Joseph Ratzinger is the first German pope in about 1,000 years.

Some information for this report provided by AFP and Reuters.