An estimated 150,000 pilgrims cheered as the pope made his way through St. Peter's Square in his popemobile. The pope stopped at times to kiss and bless children. Some in the audience waved flags and held banners showing their gratitude.
The pope acknowledged there have been difficult times during his papacy, but also recalled moments of joy and light. The 85-year-old told the Catholic faithful to pray for his successor, and he once again explained his reasons for stepping down after eight years.
Benedict said that "to love the church means also to have the courage to take difficult, painful decisions, always keeping the good of the church in mind, not oneself."Many of the cardinals who will choose Benedict's successor were also in the crowd for his final public audience including Los Angeles Cardinal Roger Mahony. The cardinals gave him a standing ovation at the end of his speech.
Mahony has been criticized for covering up priestly abuse of minors. When reporters asked Mahony his response to those outside the Vatican who don't want him in the conclave, he said, "God bless you" and kept walking.
There were many Americans on hand. Julia Hawkes of Los Angeles and two of her college friends said they wanted to hear his words, knowing the last time a pope retired was 600 years ago.
"This is such a monumental time. No pope has resigned the way he has done. It's something that we have to see," said Hawkes.
The pope's tenure has been beset by the clerical sex abuse scandal, discord over everything from priestly celibacy to women's ordination, and most recently the betrayal by his own butler who stole his private papers and leaked them to a journalist. Some say the scandals tarnish his legacy.
"It seems like he's taking off right in the middle of it and doesn't want to solve the problem. It's easier just to leave," said Darlene Niewski, who was visiting Rome from New York.
The pope will meet with cardinals on Thursday for the last time and then fly by helicopter to the papal residence in Rome. He will greet parishioners from the palazzo's balcony. It'll be his final act as pope before his retirement officially begins Thursday night.
After Thursday night, Pope Benedict will be referred to as his holiness Pope Emeritus. And you won't see any more tweets from the pontiff. He's also retiring his Twitter account.
On Monday, the cardinals will decide the date of the next conclave to elect a new pope. Normally the cardinals are not allowed to select a new pope until 15 to 20 days after the office becomes vacant, usually when the previous pope dies. But Pope Benedict has made it possible for cardinals to elect his successor faster.