Benedict has been living in Castel Gandolfo, the summer papal residence outside Rome, since his shock resignation at the end of February.
But it was always a temporary arrangement and the German-born former pontiff will move into his new retirement home within the Vatican gardens this afternoon.
The 86-year-old ex-Pope will be picked up by helicopter from the grounds of Castel Gandolfo, which perches on the rim of a volcanic crater lake, and flown to the Vatican, a 15 minute flight away.
He will take up residence in a former convent in the Vatican's extensive gardens. Situated on a hill within the city state, it commands views of St Peter's Basilica, the rooftops of Rome and the Apennine mountains.
It is a 10 minute walk from Casa Santa Marta, the Vatican residence where Pope Francis has chosen to live since his election, having rejected the option of living in the much larger and more lavish papal apartments.
The two popes will be dressed very similarly – as Pope Emeritus, Benedict wears a white cassock, while Francis wears a white cassock with a short cape around his shoulders.
Vatican observers have speculated that the presence of a "shadow Pope" could cause difficulties for Francis, but Vatican officials insist that Benedict intends to devote the rest of his life to study and prayer and will not be making public pronouncements which could contradict those of his successor.
When he announced his decision to step down, Benedict said he would live out his remaining days "hidden from the world".
Benedict will live on the ground floor of the convent, which has undergone extensive renovations.
He will be accompanied by a small staff, including his personal secretary, Archbishop Georg Ganswein.
Benedict looked pale and bowed the last time he was seen in public, on March 23, when he welcomed Francis to Castel Gandolfo – the first time that an ex-Pope had met a living Pope since the 13th century.
Benedict's frail appearance contrasted with that of the much more robust-looking Pope Francis.
The
Vatican insists that Benedict does not have a serious illness or
medical condition, but is simply slowing down as a result of his
advanced age.