At inaugural, Pope Francis vows to serve poor Urges those in power to protect world ← Related Article Visit The Boston Globe Share on Twitter Share on Facebook Comment on this Scroll to top of page AP Photo/Michael Sohn Pope Francis waved to the fervent crowd as he arrived to his installation Mass in St. Peter's Square. ALESSANDRO BIANCHI/REUTERS Francis took part in his inaugural Mass in St. Peter's Square on Tuesday. AP Photo/Riccardo De Luca Among the hundreds of dignitaries in attendance was Vice President Joe Biden. STEFANO RELLANDINI/REUTERS The fisherman's ring was placed on the finger of Pope Francis by Cardinal Angelo Sodano, dean of the College of Cardinals. Gregorio Borgia/AP Nuns listened as Pope Francis read the gospel. Andrew Medichini/AP Cardinals attended Pope Francis's inaugural Mass. AP Photo/Gregorio Borgi During his inaugural Mass, Francis was interrupted by applause several times. Andrew Medichini/AP Priests lined up in St. Peter's Square. Jeff J Mitchell/Getty Images Hundreds of thousands packed St. Peter's Square for the pope's installation Mass. AP Photo/Michael Sohn A priest delivered communion to the faithful in St. Peter's Square. AP Photo/Riccardo De Luca German Chancellor Angela Merkel attended the installation of the new pope. AP Photo/Dmitry Lovetsky French Prime Minister Jean-Marc Ayrault was among the world leaders who attended the Mass. Stefano Rellandini/REUTERS Zimbabwe's President Robert Mugabe and his wife Grace attended the Mass. Paul Hanna/REUTERS Spain's Prince Felipe (left) and Princess Letizia, and Spain's Prime Minister Mariano Rajoy (right) were in attendance. EPA/ETTORE FERRARI Pope Francis waved to the crowd from an open-air vehicle. Gregorio Borgia/AP Pope Francis arrived to his installation Mass. Dmitry Lovetsky/AP Pope Francis got out of his vehicle to bless a disabled man prior to the Mass. Christopher Furlong/Getty Images Many of the faithful took photos of Francis as he made his way through St. Peter's Square. AP Photo/Riccardo De Luca Pope Francis reached for a child during his tour through St. Peter's Square at the Vatican. ENRIQUE MARCARIAN/REUTERS Argentines watched the inaugural Mass on a giant screen next to the Metropolitan Cathedral in Buenos Aires. AP/Natacha Pisarenko A woman held a sign as she watched the installation from Buenos Aires. ENRIQUE MARCARIAN/REUTERS Faithful carried a Vatican flag as they waited to watch a broadcast of the inaugural Mass in Buenos Aires. AP Photo/Gregorio Borgia Argentina's President Cristina Fernandez de Kirchner, left, greeted Dutch Prince Willem-Alexander. ALESSANDRO BIANCHI/REUTERS Chalices containing hosts were prepared before the Mass. REUTERS/Max Rossi Nuns ran through St. Peter's Square to get a good vantage point.