In a secretive process refined over centuries, the Catholic Church's College of Cardinals will 'enter a conclave' later this month to elect Christendom's 266th pope, to succeed Benedict XVI, who resigned last month. These scarlet-clad prelates will be literally locked inside a Vatican chapel until they nominate a new pontiff from among themselves.

ELECTION
The papal election is conducted in absolute secrecy and can go on for days or even weeks. Only cardinals under the age of 80 can take part in the conclave. 115 of them, dubbed 'cardinal-electors', are currently expected to participate in this one. To prevent factionalism Benedict XVI mandated that a 'supermajority' of two-thirds-plus-one vote is required to elect a pope, which means compromise will always determine the winner.

Votes are held consecutively until a cardinal achieves the majority. The first vote is taken on the first afternoon after a Mass, and is followed by two on the morning of the next day and two in the evening, and so on. After 3 days with no result the voters may take a break.

During a vote, each cardinal is handed a printed ballot to fill in his choice for pope. He does it in confidence, folds it twice, walks up to the altar, places it on a plate, says a prayer and then tips it into a large chalice.

After voting, three cardinals (dubbed scrutineers) read out names as they tally the vote. The ballots are then strung together and burned. A record, later sealed, is kept for the Vatican archives.

The burning of the ballots is the age-old means of communicating the result to the world. If no one has been elected, a dye is added to make the smoke venting up a 60-foot chimney black. When a pope is elected the smoke will be white.

Once a cardinal is elected the senior prelate asks him if he accepts election. (Some have apparently refused in the past. ) The winner is then asked what papal name he desires, after which all cardinals individually pledge allegiance to the new pope.