Affectionately called the "saint of the gutters" during her lifetime, Mother Teresa of Calcutta will be made an official saint of the Roman Catholic Church tomorrow, just 19 years after her death.
A Nobel peace prize winner, Mother Teresa was one of the most influential women in the Church's 2000-year history, acclaimed for her work among the world's poorest of the poor in the slums of the Indian city now called Kolkata.
Hundreds of thousands of faithful are expected to attend the canonisation service for the tiny nun, which will be led by Pope Francis in front of St Peter's basilica.
Although criticised both during her life and following her death, Mother Teresa is revered by Catholics as a model of compassion who brought relief to the sick and dying, opening branches of her Missionaries of Charity (MoC) order around the world.
"Even in popular culture she's identified with goodness, kindness, charity," said Father Brian Kolodiejchuk, the MoC priest who campaigned for her sainthood.
In novels or movies often characters say, "Oh, who do you think I am? Mother Teresa?" he told Reuters.
Her critics, however, view her differently, arguing she did little to alleviate the pain of the terminally ill and nothing to stamp out the root causes of poverty.
In 1991, the medical journal Lancet visited a home she ran in Kolkata for the dying and said untrained carers failed to recognise when some patients could have been cured.
Kolodiejchuk said her detractors missed the point of her mission, arguing that she had created a place to comfort people in their final days rather than establish hospitals.
"We don't have to prove that saints were perfect, because no one is perfect," he said.