(We last updated the top of this post at 2 p.m. ET.)
Precisely on time, under dark skies but with the lights of cameras from news outlets around the world illuminating the scene, Swiss Guards on Thursday closed the doors of the palazzo at Castel Gandolfo south of Rome — marking the official end of Pope Benedict XVI's time as head of the Roman Catholic Church.
For the first time in about 600 years, a pope has voluntarily stepped down. His final moment as leader of the church came at 8 p.m. local time (2 p.m. ET).
Benedict began his final day as pope by promising "unconditional reverence and obedience" to the man who will take his place. He will become "pope emeritus" and begin a life in which he's expected to be out of the public eye, living in a former monastery. Benedict, 85, has said he no longer has the strength to lead the church.
The pope left the Vatican in the late afternoon. As his helicopter was about to depart for the short flight to the papal retreat south of Rome, the pope's official Twitter page posted what is expected to be the last tweet from Benedict: "Thank you for your love and support. May you always experience the joy that comes from putting Christ at the centre of your lives." Moments later, the helicopter lifted off the ground. It circled the Vatican. Below, some in the crowd could be seen holding signs saying "thank you" in various languages.
After arriving at the retreat, Benedict appeared on a balcony for what may be his last appearance in public. He thanked those there to see him and said he was embarking on a new chapter in his life, as a pilgrim.
Benedict's pledge of obedience to his successor came during "an unexpected speech" to the church's cardinals Thursday in Vatican City, The Associated Press writes. According to the wire service:
"Benedict also urged the 'princes' of the church to set aside their differences as they elect the next pope, urging them to be unified so that the College of Cardinals works 'like an orchestra' where 'agreement and harmony' can be reached despite diversity. He said he would pray for the cardinals in coming days as they choose his successor."
The Whispers in the Loggia blog has an English transcript of Benedict's remarks posted here.
John Allen, the senior correspondent for the National Catholic Reporter who's going to be on the cable news networks a lot in coming weeks as they tap his expertise, told CNN that most of the 100+ cardinals who will cast votes for the next pope are already in Rome. They're "here to say goodbye" to Benedict, he said.
He expects they will meet Monday in what's known as a "general congregation" to set a date for the conclave — the session at which they vote for a pope. Allen expects the conclave will start "sometime around the 8th or 9th of March." The cardinals' goal will be to have a pope chosen before Palm Sunday, which this year falls on March 24.
Allen's "quick course in conclave 101" is online here. One thing it doesn't take into account is the word this week that Benedict said the cardinals don't have to wait for 15 days after he steps down to begin.