Isadora Duncan was born in San Francisco, the youngest of the four children of Joseph Charles Duncan (1819–1898), a banker, mining engineer and connoisseur of the arts, and Mary Isadora Gray (1849–1922). Her brothers were Augustin Duncan and Raymond Duncan; her sister, Elizabeth Duncan, was also a dancer. Soon after Isadora's birth, her father was exposed in illegal bank dealings, and the family became extremely poor.became extremely poor.