When a pope dies, the Roman Catholic Church begins the elaborate rituals that mark the end of one papacy and the start of the next.
The pope's camerlengo (chamberlain) has to officially confirm his death and then seals his private apartment, prepares the funeral and the conclave to elect a successor.
The camerlengo and three assistants chosen by lot from among the cardinal electors to decide when the pope's body is to be taken into St Peter's Basilica for public viewing. They also make sure the Pope's Fisherman's Ring and his lead seal are broken so they cannot be used by anyone else. No autopsy is performed.
Funeral rites last nine days, with the date of the funeral and burial to be decided by the cardinals between the fourth and sixth day after his death. Popes are laid to rest in the crypt underneath St Peter's Basilica.
They are traditionally buried in a casket of cypress wood which is sealed inside a larger lead casket and then covered with an outer pine box.
The College of Cardinals oversees day-to-day business during the interregnum. Their power is limited and much of the central Church administration grinds to a halt.
The conclave to elect a new pope starts in the Vatican's Sistine Chapel between 15 and 20 days after the death. The cardinals, who are confined to the Vatican for the duration of the conclave, decide the exact day. For the first time, they will not live in the chapel or nearby rooms in the Vatican Museum, but in a new residence on Vatican grounds.
There are 117 cardinals under the age of 80 and so eligible to vote. Only two were not appointed by John Paul. They need a majority of at least two thirds plus one to elect the new pope.
When the conclave has elected a pope, he is asked if he accepts and which name he wishes to take. Once this is done, he dons papal vestments - tailors keep several sizes ready - and sits on a throne in the Sistine Chapel to receive the other cardinals, who file up to pay homage and pledge obedience.
The world will know a pope has been elected when an official burns the paper ballots with special chemicals to make white smoke pour out of the chapel's chimney. They use other chemicals to make black smoke indicating an inconclusive vote.
Soon afterwards, the dean of the College of Cardinals steps on to the central balcony of St Peter's Basilica to announce to the crowds in the square Habemus Papam (We have a Pope). The new pope then appears in his papal robes and gives the crowd his blessing.