The pontiff appeared to be trying to defuse concerns about possible conflicts arising from the peculiar situation of having a reigning pope and a retired one.

Pope Benedict XVI promised his “unconditional reverence and obedience” to his successor in his final words to his cardinals on Thursday, a poignant farewell before he becomes the first pope in 600 years to resign.

The pontiff appeared to be trying to defuse concerns about possible conflicts arising from the peculiar situation of having a reigning pope and a retired one.

Delivering an unexpected speech, Benedict also urged the “princes” of the church to set aside their differences as they elect the next pope, urging them to be unified so that the College of Cardinals works “like an orchestra” where “agreement and harmony” can be reached despite diversity.

“Among you is also the future pope, whom I promise my unconditional reverence and obedience,” Benedict said in his final audience.

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

But Benedict has tried to address those worries, saying that once retired he would be “hidden from the world.” In his final speech in St. Peter’s Square on Wednesday, he said he wasn’t returning to private life, but rather to a new form of service to the church through prayer.

Shortly before 5 p.m., Benedict will leave the palace for the last time as pontiff, head to the helipad at the top of the hill in the Vatican gardens and fly to the papal retreat at Castel Gandolfo south of Rome.

There, at 8 p.m. sharp, Benedict will become the first pontiff in 600 years to resign. The doors of the palazzo will shut and the Swiss Guards will go off duty, their service protecting the head of the Catholic Church over for now.

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