Armenian Catholic patriarch Nerses Bedros XIX Tarmouni, left, greets Pope Francis at the end of an Armenian-Rite Mass on the occasion of the commemoration of the 100th anniversary of the Armenian Genocide, in St. Peter's Basilica, at the Vatican, Sunday, April 12, 2015. Pope Francis on Sunday honored the 100th anniversary of the slaughter of Armenians by calling it "the first genocide of the 20th century," a politically explosive declaration that will certainly anger Turkey. (AP Photo/Gregorio Borgia)