Benedict XVI's time as pope came to a historic end Thursday, as he became the first pontiff in six centuries to resign as leader of the world's Roman Catholics, who now number 1.2 billion.
Torchlit crowds stood before the gates of the Castel Gandolfo residence, waiting to see the Swiss Guards, the soldiers who traditionally protect the pope, salute and close the doors on the stroke of 8 p.m.
The guards' departure from the papal summer home brings Benedict's papacy to a formal end. The protection of Benedict there falls now to Vatican police.
The process of transition to that new pope now begins. Meanwhile, the Catholic Church is without a leader.
Symbolizing that gulf at the top, all Benedict's tweets as @Pontifex have been archived. Instead, the account's Twitter page reads only "Sede Vacante," or empty seat.
Earlier, his final words were given to some 10,000 people who had gathered at Castel Gandolfo to bid him an emotional farewell.
"I am no longer the pope but I am still in the church. I'm just a pilgrim who is starting the last part of his pilgrimage on this earth," he said.
He thanked them for their friendship, on a day "different for me than the preceding ones" -- and indeed almost unprecedented for the Roman Catholic Church.
"I would still -- with my heart, with my love, with my prayers, with my reflection, and with all my inner strength -- like to work for the common good and the good of the church and of humanity," he said.
"I feel very supported by your kindness. Let us go forward with the Lord for the good of the church and the world. Thank you."
Smiling slightly, he made the sign of the cross to bless the crowds and disappeared into the building.
It is likely to be the last time he is seen in public.
Benedict, who will now be known as "pontiff emeritus," will spend the next few weeks at the peaceful, hilltop Castel Gandolfo residence before moving to a small monastery within the Vatican grounds.
The first pope to resign in 598 years, his departure ushers in a period of great uncertainty for the church as the cardinals work to elect the next pontiff.
Pomp and ceremony
Benedict earlier left Vatican City for the last time as pope amid pomp and ceremony.
An honor guard of Swiss Guards lined up to bid him farewell as, looking frail and carrying a cane, he left the papal apartment to applause from senior Vatican officials and staff.
The sound of bells from St. Peter's Basilica chimed across the city of Rome as the helicopter carrying him to Castel Gandolfo looped overhead, passing above landmarks like the Colosseum.
Although Benedict will eventually return to Vatican City to live out his days, he will never again set foot there as pope.
Seals will be placed on the entrance to the pope's Vatican apartment, the Vatican said -- to be removed only when the next pontiff enters.
His symbolic Fisherman's Ring and papal seal will be "destroyed" by means of making scratch marks so that they can no longer be used to seal documents, said Vatican spokesman Federico Lombardi.
Benedict's final tweet, sent at 11 a.m. ET from his @Pontifex account, read: "Thank you for your love and support. May you always experience the joy that comes from putting Christ at the centre of your lives."
The account will remain dormant until the next pope decides whether he wants to use it, the Vatican said.
Benedict entered his final day as pontiff with an unusual act -- a pledge of "unconditional obedience" and respect to whoever takes up the reins after his dramatic resignation later.
His promise came in a last meeting Thursday morning with the cardinals who will pick his successor, almost certainly from within their own ranks.
"I will continue to serve you in prayer, in particular in the coming days, so that you may be touched by the Holy Spirit in the election of a new pope," he said.
His words appeared designed to answer concerns that the presence of a former pontiff might lead to confusion or competing loyalties once the new pope is installed.
Benedict told the cardinals it was a "joy to walk with you" during his nearly eight tumultuous years at the head of all Catholics worldwide.
Another Vatican spokesman, the Rev. Thomas Roscia, said he believed 144 cardinals had attended Benedict XVI's farewell to them as pope. That includes both cardinal-electors, who are under the age of 80, and cardinals who are not eligible to vote for the next pope.
Not all the 115 cardinals eligible to vote were present, Lombardi said.
Two cardinals are suffering ill health, making their attendance uncertain, although arrangements may be made to enable them to vote, Roscia said.
The Vatican has said it wants to have the next pontiff in place in time for the week of services leading up to Easter Sunday on March 31.
A series of meetings to set the timetable for the conclave -- the closed-door assembly to elect a new pope -- will begin early next week, said Lombardi. The cardinals will receive the formal invitation to attend on Friday.
The meetings, known as general congregations, bring together all the cardinals, electors and non-electors, before the conclave begins. They are intended to be an opportunity to reflect on the current state of the church.
In their meeting Thursday morning, the cardinals gave Benedict a standing ovation, and then one by one each met Benedict to say a final few words.
Cardinal Daniel DiNardo of Texas said at a news conference held with fellow U.S. cardinals that it had been "a very moving moment with Pope Benedict."
"There was a note of sadness in saying farewell to this man who has been our spiritual father for the last eight years," said Cardinal Sean O'Malley of Boston.
"At the same time it was very edifying to see how much people love him and respect him."