Pope Francis has flown in for lunch with his predecessor, Pope Emeritus Benedict XVI, in a cliff-top castle outside Rome - the first such encounter for nearly 720 years.
The Argentine Pope flew in by helicopter from the Vatican to Castel Gandolfo, where his German predecessor is enjoying the first few weeks of his retirement following his shock decision to resign last month.
The Vatican said the two popes embraced on the helipad.
In the chapel where they prayed together, Benedict offered Francis the traditional kneeler used by the pope. Francis refused to take it alone, saying "We're brothers," and the two prayed together on the same one.
The Vatican spokesman, Rev Federico Lombardi said he understands Benedict offered his pledge of obedience to the new pope, while Francis thanked Benedict for his ministry.
He said they both wore white, though Benedict was in a simple cassock without the traditional sash and cape worn by Francis.
Crowds gathered in the central square of Castel Gandolfo this morning to catch a glimpse of something that has not been seen in centuries: two Popes together.
After Francis's 15 minute helicopter ride, the two Popes – both dressed in white vestments – will sit down for a meeting before having lunch together in the magnificent castle, which is perched on the edge of an escarpment that plunges down to a cobalt blue volcanic lake.
The Vatican spokesman promised a general comment about the meeting, but no detailed statement.
There has been enormous speculation about what the two men in white might have to say to one another after making history together. Benedict's unprecedented resignation paved the way for the first pope from Latin America, the first Jesuit, and the first to call himself Francis after the 13th century friar who devoted himself to the poor, nature and working for peace.
Popes traditionally serve until death and only a handful have resigned in the Church's 2,000 year history, many of them under duress as a result of schisms and factional feuds.
Benedict's resignation - the emeritus pope's personal choices about his future - have raised the question of how the Catholic Church will deal with the novel situation of having one reigning and one retired pope living side-by-side, each of them called "pope," each of them wearing papal white and even sharing the same aide in Monsignor Georg Gaenswein.
Not since the 13th century has a Pope had the chance to meet – much less have lunch with – his living predecessor.
In 1294, Pope Celestine V became one of the very few Popes to resign, complaining that he had never wanted the role in the first place.
He had accepted the office with the greatest reluctance five months before – he had been living as a bearded hermit in the wilds of the Apennines when a group of cardinals insisted that he was the man for the job.
Celestine V held discussions about his decision to quit with Cardinal Benedetto Gaetani, who succeeded him and took the name Boniface VIII.
The ex-Pope then fled Rome as quick as he could, anxious to resume his life as a cave-dwelling ascetic in the Abruzzo region of central Italy.
Unfortunately for him, Boniface VIII saw him as a threat, fearing that enduring loyalties to the former pontiff could provoke a schism.
He had Celestine arrested, hauled him back to Rome and imprisoned him in a castle at Ferentino, about 40 miles south-east of the city. Celestine died there ten months later, in May 1296.
His cell was so cramped that, according to one contemporary account, "the spot whereon the saint stood when saying Mass was the same as that whereon his head lay when he reclined".
"Boniface kept him in miserable conditions until his death. There's no evidence that he deliberately had him bumped off but he certainly kept him in terrible conditions," said Rebecca Rist, a Church historian from the University of Reading.
It has been suggested that the lingering presence of the 85-year-old Benedict could encourage divisions within the Church, with a "shadow Pope" becoming a focus for dissatisfaction with the new pontiff.
Dr Rist thinks that is unlikely. "Benedict is a very shy, retiring and studious type. I think he genuinely wants to get out of the limelight. He saw what happened in the last years of John Paul II's papacy, when things got out of control because of his illness. He didn't want the same thing to happen. I think Francis very much has Benedict's blessing."