Pope Benedict resignation: Pontiff waves goodbye to Papacy from balcony of summer retreat

Benedict XVI has left the Vatican for the last time as pope, flying by helicopter to the Vatican's vacation retreat hours before becoming the first pontiff to resign in 600 years.

As his closest aide wept by his side, Benedict bade farewell to Vatican officials gathered in the San Damaso courtyard of the Apostolic Palace, a corps of Swiss Guards standing by at attention.

Benedict travelled by car to the helipad on the top of the hill of the Vatican gardens and boarded a helicopter along with his secretary, Monsignor Georg Gaenswein, for the 15-minute trip to Castel Gandolfo. Bells tolled as the helicopter took off.

Before leaving, Benedict pledged his "unconditional reverence and obedience" to his successor.

The pontiff has insisted that once retired, he will be 'hidden from the world', defusing concerns that his decision to live in the Vatican in retirement may cast a shadow over his replacement.

This morning, Pope Benedict had said his goodbyes to more than 100 cardinals at a gathering in the Clementine Hall in the Apostolic Palace.

The Pope was greeted by well-wishers when his helicopter landed at the pad in Castel Gandolfo.

The helicopter had circled St. Peter's Square, where people held up signs saying "Thank You".

Earlier in an unexpected address inside the Vatican's frescoed Clementine Hall, the pope appeared to be trying to defuse concerns about his future role and the possible conflicts arising from the peculiar situation of having both a reigning pope and a retired one.

Benedict also gave a final set of instructions to the "princes" of the church who will elect his successor, urging them to be united as they huddle to choose the 266th leader of the world's 1.2 billion Catholics.

"May the College of Cardinals work like an orchestra, where diversity - an expression of the universal church - always works toward a higher and harmonious agreement," he said.

It was seen as a clear reference to the deep internal divisions that have come to the fore in recent months following the leaks of sensitive Vatican documents that exposed power struggles and allegations of corruption inside the Vatican.

The audience inside the Apostolic Palace was as unique as Benedict's decision to quit, with the 85-year-old pope, wearing his crimson velvet cape and using a cane, bidding farewell to his closest advisers and the cardinals themselves bowing to kiss his fisherman's ring for the last time.

Related: Pope holds last audience in St Peter's Square (slideshow)

Some seemed to choke up at that moment, and a few lingered on to chat with the pope for as long as they could. But the scene seemed otherwise almost normal, with cardinals chatting on the sidelines waiting their turn to say goodbye.

Benedict said he would pray for the cardinals in coming days as they discuss the issues facing the church, the qualities needed in a new pope, and prepare to enter into the secret conclave to elect him.

"Among you is also the future pope, whom I today promise my unconditional reverence and obedience," Benedict told the cardinals.

Benedict's decision to live at the Vatican in retirement, be called "emeritus pope" and "Your Holiness" and wear the white cassock associated with the papacy has deepened concerns about the shadow he might cast over the next papacy.

Within a couple of months, the pope is expected to return to the Vatican and take up residence in an ex-nunnery with breathtaking views of Rome surrounded by extensive well-manicured gardens.