JOIN USCatholics from around the world gathered in Rome today for a mass presided by Pope Francis to confer sainthood on John Paul II and John XXIII -- two influential popes who helped shape 20th century history.
A million pilgrims were expected and thousands could be seen camped out in and around the Vatican, sleeping in folding chairs, praying in silence with rosary beads and singing religious chants.
Polish faithful danced around the fountains of Piazza Navona and pilgrims attended vigils across the Eternal City ahead of a ceremony seen as a way of uniting conservative and reformist strands of Catholicism.
"This is a special moment in history. The skies will open and it is going to be an extraordinary day!" said Sister Lucia Vittoria, a Brazilian living in Italy who camped out in the streets along with nine fellow nuns.
Francis will co-celebrate the open-air ceremony from 0800 GMT with pope emeritus Benedict XVI and hundreds of bishops and cardinals gathered near the altar, under giant tapestry portraits of the two late pontiffs.
This is the first time that a ruling pope and a living former pontiff celebrate mass jointly and the first time that two popes are canonised on the same day.
Francis has reached levels of popularity not seen since the glory days of John Paul II but is more comparable to John XXIII, a down-to-earth unifying figure.
By sainting them together, Francis "is speaking not just to the outside world but to rival camps within the Catholic fold who see John XXIII and John Paul II as their heroes", said US-based Vatican expert John Allen.
The ceremony will be relayed in different languages on giant screens around the city including at Fiumicino airport, the Colosseum and Piazza Navona, a square built on the site of the stadium of Domitian.
It is also being shown in 3D at cinemas across the world from Francis's native Argentina to Lebanon and live tweeted under the Vatican hashtag #2popesaints.
"It will be a great feast for our parish and especially for us Catholics who will all be united," Joseph Vinecker, a German priest at a night-time prayer vigil who said he was looking forward to "a mythical day".
Elizavet Kendzha, a Polish pilgrim, hailed John Paul II's role in helping topple Communism in her country and many of the flags around her were for Solidarity, the trade union protest movement he helped foster.
The Vatican said 98 foreign delegations would attend including former Polish president and Solidarity leader Lech Walesa and the kings of Belgium and Spain.