VATICAN CITY — Pope Francis declared his predecessors Pope John Paul II and Pope John XXIII saints on Sunday — in the first dual canonization ceremony in the history of the Roman Catholic Church.
In a sober address in Latin, Francis recited the words: "We declare and define Blessed John XXIII and John Paul II to be saints and we enroll them among the saints, decreeing that they are to be venerated as such by the whole Church."
The massive crowd erupted into cheers and applause, flags waving nearly as far as the eye could see.
The two famous predecessors' relics sat on the altar - a drop of blood for John Paul II and a small piece of flesh for John XXIII.
Some 500,000 pilgrims from all over the world gathered in and around St. Peter's Square for the elaborate event, some queuing for up to 15 hours to stake out their precious spot in history.
Nearly 1 million people were estimated to have descended on Rome, with hundreds of thousands watching on massive screens set up around the Italian capital. Many millions more watched the spectacle on television from the four corners of the earth.
In another unprecedented first, retired Pope Benedict XVI attended the ceremony, the first time a reigning and retired pope celebrated Mass together in public.
The entire Via della Conciliazione, the half-mile-long boulevard leading from the Tiber River to the Vatican, was crowded with the faithful. Most were Polish, having traveled from their home country or from their communities in far-flung cities in the U.S. and even Australia.
"Four popes in one ceremony is a fantastic thing to see and to be at, because it is history being written in our sight," marveled one of the visiting Poles, David Halfar. "It is wonderful to be a part in this and to live all of this."
John Paul II, the Pole who reigned for nearly 27 years, witnessed the devastation of his homeland in World War Two and is credited by many with helping end the Cold War and bring down communism.
While both men were widely revered, there has also been criticism that John Paul II, who died just nine years ago, has been canonized too quickly.
Groups representing victims of sexual abuse by Catholic priests also say he did not do enough to root out a scandal that emerged towards the end of his pontificate and which has hung over the church ever since.
John, an Italian often known as the "Good Pope" because of his friendly, open personality, died before the Second Vatican Council ended its work in 1965 but his initiative set off one of the greatest upheavals in Church teaching in modern times.
The Council ended the use of Latin at Mass, brought in the use of modern music and opened the way for challenges to Vatican authority, which alienated some traditionalists.
— Reuters and The Associated Press contributed to this report.