Pope Benedict leaves Vatican
A helicopter carrying Pope Benedict XVI lifts off from Vatican City on the way to Castel Gandolfo. Photograph: Peter Macdiarmid/Getty Images
The papacy became vacant at 8pm (1900 GMT/2PM ET), marking the first time in six centuries a pope has resigned instead of ruling for life.
In a symbolic gesture, the Swiss Guards who stood sentry at the papal summer residence south of Rome, where the pope flew by helicopter less than three hours earlier, quit their posts and the massive wooden doors of the hilltop residence were closed.
At the same time, the papal apartments in the Vatican were locked and will not be opened until a new pope is elected.
As he left the Vatican several hours earlier by helicopter, he sent his last Twitter message: "Thank you for your love and support. May you always experience the joy that comes from putting Christ at the centre of your lives."
Bells rang out from St Peter's Basilica and churches all over Rome as the helicopter circled Vatican City and flew over the Colosseum and other landmarks to give the pontiff one last view of the city where he is also bishop.
"As you know, today is different to previous ones," he told an emotional, cheering crowd holding balloons and banners after he arrived in the small town of Castel Gandolfo, where the summer residence it located.
He told the crowd, many of whom were crying, that he would soon become "simply be a pilgrim who is starting the last phase of his pilgrimage on this earth".
He then turned and went inside the villa, never to be seen again as pope.
"I wanted to see him for the last time. I hope his successor follows in his footsteps. I feel very moved to be here," said Giuseppe Ercolino, a 19-year-old student from a nearby town.
In an emotional farewell to cardinals on Thursday morning in the Vatican's frescoed Sala Clementina, Benedict appeared to send a strong message to the top echelons of the Church as well as the faithful to unite behind his successor, whoever he is.
"I will continue to be close to you in prayer, especially in the next few days, so that you are fully accepting of the action of the Holy Spirit in the election of the new pope," he said. "May the Lord show you what he wants. Among you there is the future pope, to whom I today declare my unconditional reverence and obedience."
The pledge, made ahead of the closed-doors conclave where cardinals will elect his successor, was significant because for the first time in history, there will be a reigning pope and a former pope living side by side in the Vatican.
Some church scholars worry that if the next pope undoes some of Benedict's policies while his predecessor is still alive, Benedict could act as a lightning rod for conservatives and polarise the 1.2 billion-member church.