All 133 cardinals eligible to elect Pope Francis’s successor have arrived in Rome for the conclave. They will take their oaths to observe ‘absolute and perpetual secrecy’ in the Sistine Chapel on Wednesday,

Francis’ successor will be selected by cardinals at the conclave that begins on May 7. Cardinals, known as the “princes of the church,” rank just below the pope in the Roman Catholic Church; together, they are known as the College of Cardinals. When a pope dies, the college chooses a successor.

As the conclave gets underway, eyes are searching for the billowing white smoke that signals Habemus Papam: “We have a pope.”