Pope John XXIII leads the opening session of the Second Vatican Council in St. Peter's Basilica Oct. 11, 1962. A total of 2,540 cardinals, patriarchs, archbishops and bishops from around the world attended the opening session. Pope Benedic t XVI will mark the 50th anniversary of the council opening and kick off the Year of Faith with an Oct. 11 Mass in St. Peter's Square.