ROME-As Christendom awaits the canonisation of two beloved popes, the Eternal City battles to welcome as many as seven million people for the historic moment. On Sunday April 27 in a celebratory mass, John XXIII and John Paul II will be raised to sainthood by Pope Francis.

 Some 1 million people attended John Paul’s 2011 beatification but the scale of this year’s ceremonies climaxing his canonisation is still more of a logistic headache. Estimates of people attending have grown from five to seven million, including 300,000 from Poland alone. Arrangements for transporting the huge throng of pilgrims from airports and train stations to the Vatican, providing water, toilets and first aid, has required constant adjustment. “We have created a special team which will work with the one coordinated by the Vatican Secretary of State, Cardinal Pietro Parolin,” said Mayor of Rome Ignazio Marino. “It is an historic event.”

 By March, according to the Rome hotel owners’ association, more than 82 percent of hotel rooms had been booked for the canonisation weekend. In September Francis announced his plan to proclaim the pontiffs saints in a joint ceremony on Divine Mercy Sunday. Immediately the Prefecture of the Papal Household disclosed that access to St Peter’s square would be first-come, first-served, and warned against tour operators selling fake tickets to the Sunday mass.

 When in 2005 thousands of pilgrims gathered to bid farewell to the late Karol Wojtyla, St Peter’s Square was enlivened by voices chanting “santo subito,” “(saint immediately)” yet the road to sainthood has necessary stages which cannot be sped up.

 In July Francis signed a decree recognising the healing of a Costa Rican woman with a brain aneurysm as the second miracle necessary for Blessed John Paul to be canonised, after his first miracle had served as proof of beatitude.

 The same day it was announced that the Argentinian pope and the members of the Congregation for Saints’ Causes agreed that the canonisation of John XXIII, the initiator of the Second Vatican Council, should go forward, even with only one confirmed miracle attributable to him.

 Cardinal Angelo Amato, the Congregation for Saints' Causes prefect, has noted, however, that the official position paper prepared for Roncalli’s cause is "full of accounts of miracles and favours granted by God through his intercession.”

 The mass in St Peter’s square will start at 10 a.m. and hundreds of thousands of people will be able to watch the ceremony on video screens in Piazza Navona, Piazza del Popolo, on Via dei Fori Imperiali and outside the Colosseum.