For the first time in 600 years, the seat of st. Peter is say gant because a living pope has returned to his quiet life. Taking off the red shoes and the papal robes. Benedict xvi took off that papal... See More
For the first time in 600 years, the seat of st. Peter is say gant because a living pope has returned to his quiet life. Taking off the red shoes and the papal robes. Benedict xvi took off that papal ring, you see on his finger. Tonight, it has been scratched with an x across the face so no one else can ever use his papal seal. And then, he turned and walked back into his new life. His academic life, with his books, his piano, his beloved cat awaiting him. As the bells tolled to mark his final day. And they are the same bells that fill the air on his first day as pope eight years ago. So, now it is time for the great debate about a new pope and a new day for the ancient church. And abc's george stephanopoulos leads us off in st. Peter's square tonight. George? Reporter: Diane, every detail was tightly scripted, highly conscious of the history he was making, benedict sent a message with every step. And tonight, his robes have been traded in, his guards have stood down. The holy leader, who hours ago led more than a billion faithful, has now become one of them. One by one they said goodbye. Benedict smiling, reminding the cardinals, "among you is the future pope." Then, it was time to go. Benedict, making the long walk through the vaulted vatican halls, cheers, waves, followed by a long, winding ride, the signs of "grazie" everywhere. The bells of st. Peter's basilica ringing out as he arrived at the heliport. Then, the defender of ancient tradition, boarding a helicopter, rising into a brilliant blue sky, rounding st. Peter's and the coliseum. Within minutes, the arrival at castel gandolfo, the vacation retreat of popes. Crowds greeting him outside his new, temporary, home. And then, one last time as pope, benedict stood on a balcony. He spoke -- saying, "i am no longer the pontiff of the catholic church. I am simply a pilgrim, beginning the last leg of his pilgrimage on this earth." Reporter: After blessing the faithful, he disappeared. And hours later, at 8:00 p.M. Local time, those swiss guards leaving their post. The gates closing. One chapter ends, a new one begins. Benedict told the cardinals today that he will be close to them in prayer as they choose his replacement. And diane, tonight, this 2,000 yeerltd church, steeped in tradition, is improvising its way into a new reality. All right, george, our thanks to you. And, of course, tonight, at the vatican, the papal apartment has been sealed with a red ribbon, awaiting a new occupant. And a moder twist. The pope's twitter account has a new message. Sede vacante. Vacant seat.
This transcript has been automatically generated and may not be 100% accurate.