But even now she was declined permission, and told instead to join an existing order that worked with the poor – though not with such desparate cases nor in such sacrificial poverty as Mother Teresa wanted.

She followed this instruction, and then in 1948, after an appeal to the Pope, she was finally granted the permission she sought.

She moved into the slums, swapping her nun's habit for the white and blue sari worn by Calcutta scavenger women. She set up a school for children, first showing them the alphabet with a stick in the mud, and then in a vacant room where they learned literacy and hygiene.

Local people gave her what equipment and support they could, and local women started to join her new order, the Missionaries of Charity. They fed the slum dwellers and treated them with food and medical supplies which they themselves begged from wellwishers.

Mother Teresa insisted that to understand poverty properly and fully demonstrate the love of God, they had to live every bit as meagrely as anyone else. Sometimes after an exhauting day they would have nothing to eat but raw wheat, tough usually they managed rice and vegetables.

After her first year's work in there she reported:

"You can now hear the  children singing in the slums. Their faces brighten up with smiles when the sisters come. Their parents, too, do not ill-treat their children. This is just what I have been longing to see among the poor. Thank God."

Next: Building Nazareth