Mother Teresa was born in Macedonia in 1910 and felt called to be a missionary at age 12. She joined the Sisters of Loreto as a nun in India in 1931 where she taught school. In 1948, the poverty and suffering in Calcutta's slums moved her to leave teaching and devote herself to serving the poorest people. She founded the Missionaries of Charity in 1950 and expanded the order internationally, with over 1 million workers in 40 countries by 1990. Mother Teresa received the Nobel Peace Prize in 1979 and was beatified in 2003 for her humanitarian work helping the poor in Calcutta.