Thousands of pilgrims began a night of prayer in Rome today as Pope Francis and Benedict XVI prepared to confer sainthood on John Paul II and John XXIII in a historic effort to unite the Catholic Church.
Religious chants rang out as pilgrims settled down with sleeping bags and picnic chairs to be first in line for tomorrow's ceremony in the Vatican honouring two of modern Catholicism's most influential figures.
Some faithful posed next to cardboard cut-outs of the future saints, while others prayed with rosary beads and one group of teenagers wore baseball caps reading "Karol" in honour of the Polish pontiff Karol Wojtyla.
"We came to Rome out of love for John Paul II. Being here is a dream," said Elizavet Kendzha, a Polish pilgrim in a red poncho on Via della Conciliazione, the main avenue leading up to St Peter's Basilica.
"John Paul II gave the Polish people freedom!" the 54-year-old said, pointing to a giant portrait of John Paul II hanging from the basilica alongside one of John XXIII, remembered as "Good Pope John".
Over one million faithful are expected at what will be a unique event, with a mass presided by Pope Francis that will be co-celebrated with his 87-year-old predecessor Benedict XVI in a rare public appearance.
The pope emeritus, in his papal white cassock, will be sitting alongside red-robed cardinals near the altar.
The Vatican also said 98 foreign delegations will be attending including former Polish president Lech Walesa, whose Solidarity movement backed by John Paul II helped topple communism in eastern Europe.
The kings of Belgium and Spain were also expected, as well as Zimbabwean President Robert Mugabe, despite a ban from entering the European Union, which does not apply in the sovereign Vatican state.
The late popes will join the official roster of saints in the first-ever canonisation of two popes at the same time, which is being seen by experts as an attempt to unite conservatives and reformists.
The charismatic, globe-trotting John Paul II became an icon to conservative Catholics, while the affable Italian John XXIII gained a reformist reputation by calling the 1962-65 Second Vatican Council, which overhauled archaic Catholic rituals and beliefs.
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.
Historic churches in central Rome remained open all night today for vigils, with services offered in Arabic, English, French, Portuguese and Spanish.
Italy's civil protection agency has 3,500 volunteers on hand, including 25 Polish cultural guides and 20 psychiatrists trained in dealing with panic attacks.
The Vatican's official bureau for pilgrims said 4,000 coaches bearing pilgrims would be arriving in the run-up to the 10:00 am (0800 GMT) mass, along with special trains and boats, while other faithful will watch the canonisations in 3D at cinemas across the world, from Francis's native Argentina to Lebanon.
