It was an order. To fail would have been to break the faith. " She began her missionary work with the poor in 1948, replacing her traditional Loreto habit with a simple white cotton sari decorated with a blue border. Mother Teresa adopted Indian citizenship, spent a few months in Patna to receive a basic medical training in the Holy Family Hospital and then ventured out into the slums. Initially she started a school in Motijhil (Calcutta); soon she started tending to the needs of the destitute and starving.
In the beginning of 1949 she was joined in her effort by a group of young women and laid the foundations to create a new religious community helping the "poorest among the poor". In 1982, at the height of the Siege of Beirut, Mother Teresa rescued 37 children trapped in a front line hospital by brokering a temporary cease-fire between the Israeli army and Palestinian guerrillas. Accompanied by Red Cross workers, she travelled through the war zone to the devastated hospital to evacuate the young patients By 1996, she was operating 517 missions in more than 100 countries.
Over the years, Mother Teresa's Missionaries of Charity grew from twelve to thousands serving the "poorest of the poor" in 450 centres around the world. Mother Teresa suffered a heart attack in Rome in 1983, while visiting Pope John Paul II. After a second attack in 1989, she received an artificial pacemaker. In 1991, after a battle with pneumonia while in Mexico, she suffered further heart problems. She offered to resign her position as head of the Missionaries of Charity, but the sisters of the order, in a secret ballot, voted for her to stay. Mother Teresa agreed to continue her work as head of the order.
In April 1996, Mother Teresa fell and broke her collar bone. In August she suffered from malaria and failure of the left heart ventricle. She had heart surgery but it was clear that her health was declining. The Archbishop of Calcutta, Henry Sebastian D'Souza, said he ordered a priest to perform an exorcism on Mother Teresa with her permission when she was first hospitalised with cardiac problems because he thought she may be under attack by the devil. On 13 March 1997, she stepped down from the head of Missionaries of Charity. She died on 5 September 1997.