Mother Teresa honored as saint and model of mercy

A giant picture of Mother Teresa is displayed outside the Missionaries of Charity Mother house in Kolkata, India, Saturday, Sept. 3, 2016. For many of the poor and destitute whom Mother Teresa served, the tiny nun was a living saint. Many at the Vatican would agree, but the Catholic Church nevertheless has a grueling process to make it official, involving volumes of historical research, the hunt for miracles and teams of experts to weigh the evidence. In Mother Teresa's case, the process will come to a formal end Sunday when Pope Francis declares the church's newest saint. (AP Photo/Bernat Armangue) (The Associated Press)

Pope Francis is driven through the crowd in St. Peter's Square at the Vatican during a jubilee audience for workers and volunteers of mercy, Saturday, Sept. 3, 2016. The square hosts a ceremony Sunday expected to draw hundreds of thousands of admirers of Mother Teresa, a nun who before her death in 1997, cared for the destitute who were dying in the streets of India. (L'Osservatore Romano/Pool Photo via AP) (The Associated Press)

Pope Francis takes the paw of Leo, the Labrador which pinpointed a four-year-child who had survived in a pile of quake rubble, in St. Peter's Square at the Vatican Saturday, Sept. 3, 2016. Pope Francis on Saturday denounced what he called the modern-day sin of being indifferent to hunger, exploitation and other suffering, as he held up Mother Teresa as a model to follow, on the eve of a sainthood ceremony for the nun who cared for India’s destitute. (L'Osservatore Romano/Pool Photo via AP) (The Associated Press)

Thousands of pilgrims are thronging to St. Peter's Square for the canonization of Mother Teresa, the tiny nun who cared for the world's most unwanted and became the icon of a Catholic Church that goes to the peripheries to find lost, wounded souls.

Pope Francis is declaring Mother Teresa a saint at a Sunday morning Mass, making her the model of his Jubilee Year of Mercy and in some ways his entire papacy. For Francis, Mother Teresa put into action his ideal for the church to be a merciful "field hospital" for the poorest of the poor — both materially and spiritually.

Throughout the night, pilgrims prayed at vigils in area churches and flocked before dawn to the Vatican under heavy security to try to get a good spot for the Mass that was expected to draw more than 100,000 people.