Vatican City: April 8, 2012. (AP) Pope Benedict XVI is celebrating Easter Sunday mass in sun-drenched, flower-adorned St. Peter's Square, before tens of thousands of people. Benedict sounded hoarse and looked tired at the start of the Mass at an altar set up on the steps outside St. Peter's Basilica. Late Saturday night, the Pope held up well as he presided over a three-hour long Easter vigil service inside the church. Easter is Christianity's most joyous day. The faithful celebrate their belief that Jesus Christ rose from the dead. At the end of Easter Mass, Benedict will go to the central balcony of the basilica to deliver a speech. Benedict, who turns 85 on April 16, was wrapping up stamina-taxing Holy Week ceremonies that drew huge crowds to Rome.