Maria Callas was born in New York in 1923 to Greek parents and studied singing in Greece before moving to Italy in 1945 to begin her career as an opera singer. She became famous for her leading roles in many famous operas and for her recordings. Callas married twice, first to an Italian industrialist and later to Aristotle Onassis, though both marriages ended in divorce. She had problems with her voice in later years and stopped performing regularly. Callas died of a heart attack in Paris in 1977 at the age of 53. She is considered one of the most influential opera singers of the 20th century for her deep understanding and emotional delivery of Italian operas.