A recipient of the Nobel Peace Prize, Mother Teresa spent much of her life working as a missionary with the poor in the Indian city of Kolkata.
To her fans, Mother Teresa was a saint during her lifetime, but to her critics she was a Catholic fundamentalist determined to save souls rather than bodies.
The Albanian nun spent 20 years with the Loreto order working as a teacher before she decided to leave and dedicate her life to the poorest of the poor.
The Missionaries of Charity was born in 1979
What began as a humble one-woman operation is now a major international organisation that operates in more than 100 countries.
Mother Teresa won the support of presidents and princesses.
Her biographer, Navin Chawla says she also had influence with the man who ran West Bengal for many years, the communist leader Jyoti Basu.
Many believed the church didn't need a miracle to prove her sainthood because she was anointed one while she was alive.
She was The Saint of the Gutters
Mother Teresa has also been criticised for her anti-abortion views, for accepting money from dictators and for providing inadequate medical care in her hospices.
But biographer Navin Chawla, says much of the criticism came from the West and went largely unnoticed in India.
Mr Chawla is a former election commissioner of India who knew Mother Teresa for more than 20 years.
He tells that many a times, he had asked her whether she tried to convert people.
"She said, 'Yes I do convert, I convert you to be a better Hindu, a better Christian, a better Catholic, a better Jew, a better Sikh, a better Muslim. When you've found God it's up to you to do with him what you want.' "
