Two months after his historic resignation, Benedict XVI returned to the Vatican on Thursday, where he will live in a former monastery in an unprecedented arrangement that will see a pope and a former pope both housed in the tiny state.
It was a relatively low-key return for the 86-year-old pope emeritus, off-limits to all but the Vatican's own media service. The service announced shortly after his arrival that expected video coverage would not be provided, sparking doubts over the state of his health.
Benedict had looked extremely frail at his last public appearance in March, and has said that he will live "hidden from the world."
The unique decision to accommodate both a pope and his predecessor within the tiny city state provoked surprise in some quarters, with critics worried that Benedict's presence may make it more difficult for Francis to make St. Peter's chair his own.
Benedict's secretary Georg Gaenswein is confusingly also the head of Francis's papal household.
But during his two-month stay at Castel Gandolfo, the papal summer residence for centuries, Benedict was careful not to be seen to interfere in any way in the papal election or the beginning of Francis's reign -- and is expected by many to maintain his low profile.
Benedict left by helicopter from Castel Gandolfo outside Rome, the papal lakeside residence where he has been staying since he stepped down at the end of February, and touched down in the Vatican at 1450 GMT, where he was met by top officials including the secretary of state Tarcisio Bertone.
Pope Francis welcomed him "with great and fraternal cordiality" at the door of the former monastery which is his new home, the Vatican said in a statement.
The pair then retired to pray together.
The current pontiff has made repeated gestures of friendship towards Benedict, visiting him in Castel Gandolfo, calling him on his birthday and holding mass for him.
The German-born former pope, who resigned because of old age, moves into the Mater Ecclesiae monastery building within the Vatican grounds -- an oasis of calm with its own vegetable garden and blooming flowerbeds -- which has been renovated for him.
There Benedict plans to carry out a life of quiet contemplation and academic research.
The visit in March between Francis and Benedict sparked concerns over the latter's health, after television footage showed the ex-pontiff visibly aged and struggling to keep up with his successor, even with the aid of a walking stick.
"He is old, weakened by age, but he is not ill," Vatican spokesman Federico Lombardi said.
In the Mater Ecclesiae monastery, Benedict will live with four housekeepers from a lay religious order that has looked after him until now, as well as with Gaenswein. A room will also be reserved for Georg Ratzinger, the ex-pope's brother, for when he should visit.
Spread over three floors, the modern complex has 12 monastic cells upstairs, while the ground floor houses a kitchen, living room, library and chapel.
The cells are sparsely furnished: the only decorations to be seen are wooden crosses and a few paintings depicting scenes from religious life, according to the Vatican.
A stone's throw from St. Peter's Basilica, the monastery has until now housed Benedictine nuns, the Poor Clares -- an order founded by saints Clare and Francis of Assisi -- and sisters from the order of the Visitation of Holy Mary, who retired to a convent in November last year.
Benedict, a nature lover who used to take regular walks around the Vatican gardens, may spend his days in the monastery flower garden, where two rare types of rose, the pink "Beatrice d'Este" and white "Giovanni Paolo II", are grown.
He will also have a role in what Francis eats: peppers, tomatoes, courgettes and cabbages grown in the vegetable garden are traditionally served up in the pontiff's kitchen, as are the lemons and oranges grown on its trees.
Despite there being both a pope and a former pope within the walls of the Vatican, the papal apartments stand empty.
Francis has chosen to remain living in more modest accommodation in the Vatican's Casa Santa Marta, the hotel which hosted him and other cardinals during the papal conclave which elected him.