| Archbishop Piero Marini closes the doors of the Sistine Chapel at the Vatican before the start of the conclave. (AFP)
Vatican City, April 18 (Reuters): Roman Catholic Cardinals began a secret conclave today in the splendour of the Sistine Chapel but failed in a initial vote to find a successor to Pope John Paul.
Some two-and-a-half hours after the cardinals locked themselves away from the world inside the frescoed chapel, billows of thick, black smoke poured out of the building's chimney, indicating that the required majority had not been reached.
Crowds of expectant Italians and tourists who had waited for hours in St Peter's Square cheered when they saw the smoke signal the end of the first day of the first conclave of the third millennium.
There was a moment of uncertainty as the first grey puffs left it unclear whether the smoke was intended to be black or white ' which would have meant a pope had been chosen. But it quickly turned a dense black.
The 115 cardinal electors from 52 countries had filed into the Sistine Chapel after hearing a leading contender urge them to choose a man with the courage to defend the traditional doctrines upheld by John Paul.
Whoever eventually emerges from the conclave as leader of the 1.1 billion-member church will have to fill the vacuum left by the death of the Polish Pontiff, whose 26-year papacy was one of the most dynamic in history, but also divisive.
Accompanied by a choir chanting Latin prayers, the red-robed 'princes of the church' walked in procession into the Sistine Chapel, where Michelangelo's fresco of the Last Judgment will stare down on their deliberations.
One by one, the cardinals placed their right hand on a book of the gospels laid in the middle of the chapel, swearing an oath of secrecy and fidelity to the church.
Just hours before the conclave opened, Joseph Ratzinger, the Vatican's doctrinal watchdog for 23 years, warned fellow cardinals that they must choose a pontiff who would support traditional Church orthodoxy.
'An adult faith is not one that follows tides of trends and the latest novelties,' he told a pre-conclave Mass at St Peter's Basilica in a sermon that many Vatican watchers interpreted as a bid to promote his own candidacy. Since John Paul's death on April 2, media and bookmakers have tipped Ratzinger, a close aide of the Polish pontiff and preacher at his funeral, as the early favourite to succeed him.
Following the opening oath, Archbishop Piero Marini, the master of papal ceremonies, said in Latin 'Extra omnes' ' 'Everyone out' ' ordering non-electors to leave the room. The cardinals remained behind, sitting side-by-side on two sets of double-rowed tables that stretched down the chapel.
As the wooden doors of the Sistine Chapel closed, applause broke out in St Peter's Square where crowds of faithful had followed the opening ceremony on giant television screens.