Two months after his historic resignation, Benedict XVI was set to return 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 is expected to be a low-key return for the 86-year-old |Benedict, now pope emeritus, who looked extremely frail at his last public appearance in March and said upon his resignation that he would live "hidden from the world."
Benedict will leave 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 is expected to touch down in the Vatican at around 1430 GMT.
His successor Pope Francis will be there to welcome him back and may retire to pray with him. 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, will move 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 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.
The image and the unprecedented situation has also raised concern among some Vatican officials, mindful of the precedent of two or even three popes at the same time and the divisions that caused.
Benedict's secretary Georg Gaenswein is confusingly also the head of Francis' 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' reign -- and is expected to maintain his low profile.
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 of Assisi and Francis of Assisi -- and sisters from the order of the Visitation of Holy Mary.