Mary Teresa Bojaxhiu, better known as Mother Teresa or Saint Mother Teresa, was an Albanian-Indian Catholic nun, founder of the Missionaries of Charity and a Catholic saint. Born in Skopje, then part of the Ottoman Empire, she was raised in a devoutly Catholic family. At the age of 18, she moved to Ireland to join the Sisters of Loreto and later to India, where she lived most of her life and carried out her missionary work. On 4 September 2016, she was canonised by the Catholic Church as Saint Teresa of Calcutta. The anniversary of her death, 5 September, is now observed as her feast day.
In 1950, Mother Teresa established the Missionaries of Charity, a religious congregation that was initially dedicated to serving "the poorest of the poor" in the slums of Calcutta. Over the decades, the congregation grew to operate in over 133 countries, as of 2012, with more than 4,500 nuns managing homes for those dying from HIV/AIDS, leprosy, and tuberculosis, as well as running soup kitchens, dispensaries, mobile clinics, orphanages, and schools.