New pope opens Holy Week at Vatican POPE Francis has celebrated Palm Sunday Mass in Saint Peter's Square attended by thousands of people waving olive branches and palm fronds. The new pontiff arrived in an uncovered vehicle to start solemn Holy Week ceremonies, which lead up to Easter, Christianity's most important day. Francis wore bright red robes over a white cassock and presided over the Mass from an altar sheltered by a canopy on the steps of Saint Peter's Basilica. Cardinals, many of them among the electors who on March 13 chose the Roman Catholic church's first Latin American pope, sat in rows for the ceremony held under hazy skies on a breezy day.