The pope's death comes one day after Francis, 88, greeted Easter Sunday crowds in his popemobile. He had battled a respiratory infection for weeks.

"At 7:35 this morning, the Bishop of Rome, Francis, returned to the house of the Father," the Vatican announced on Monday. Mourners quickly gathered in St. Peter's Square in Rome to celebrate Francis, 88, and his 12 years as the leader of the Roman Catholic Church.