Thousands begin to gather in Vatican City for Pope Francis' inaugural Mass on Tuesday.<br /> <br />Up to one million people from around the world are expected to cram into St. Peter's Square and surrounding streets to join the celebration.<br /> <br />U.S. Vice President Joe Biden will be among the 130 religious and political delegations in attendance.<br /> <br />Among them will also be Ecumenical Patriarch Bartholomew from Istanbul.<br /> <br />It's the first time the spiritual head of Orthodox Christians will attend a Roman Catholic pope's inaugural Mass since the Great Schism between western and eastern Christianity in 1054.<br /> <br />Francis, the former Buenos Aires Cardinal Jorge Bergoglio, has aroused enormous enthusiasm and interest in the Catholic world.<br /> <br />(SOUNDBITE) (English) AMERICAN PILGRIM, MIKE, SAYING:<br /> <br />"It's a historical moment. I am excited to just be here, be a part of it."<br /> <br />(SOUNDBITE) (English) AMERICAN PILGRIM JERRY HORNE OF PRIESTS FOR LIFE, SAYING:<br /> <br />"We are very pleased
