Born Agnes Gonxha Bojaxhiu on August 26, 1910, in Skopje, Macedonia, in the former Yugoslavia, she was the youngest of three children. In her teens, Agnes became a member of a youth group in her local pairsh called Sodality. Through her involvement with their activities guided by a Jesuit priest, Agnes became interested in missionaries. At age 17, she responded to her first call of a vocation as a Catholic missionary nun. She joined an Irish order, the Sisters of Loretto, a community known for their missionary work in India. When she took her vows as a Sister of Loretto, she chose the name Teresa after
Saint Thérèse of Lisieux.
In Calcutta, Sister Teresa taught geography and cathechism at St. Mary's High School. In 1944, she became the principal of St. Mary's. Soon Sister Teresa contracted tuberculosis, was unable to continue teaching and was sent to Darjeeling for rest and recuperation. It was on the train to Darjeeling that she received her second call -- "the call within the call". Mother Teresa recalled later, "I was to leave the convent and work with the poor, living among them. It was an order. I knew where I belonged but I did not know how to get there."
In 1948, the Vatican granted Sister Teresa permission to leave the Sisters of Loretto and pursue her calling under the jurisdiction of the Archbishop of Calcutta.
Mother Teresa started with a school in the slums to teach the children of the poor. She also learned basic medicine and went into the homes of the sick to treat them. In 1949, some of her former pupils joined her. They found men, women, and children dying on the streets who were rejected by local hospitals. The group rented a room so they could care for helpless people otherwise condemned to die in the gutter. In 1950, the group was established by the Church as a Diocesan Congregation of the Calcutta Diocese. It was known as the Missionaries of Charity.
In 1952 the first Home for the Dying was opened in space made available by the City of Calcutta.