Walden Robert Cassotto was born May 14, 1936, in the East Harlem neighborhood of New York City. His maternal grandfather, Saverio Antonio "Big Sam Curly" Cassotto (born January 26, 1882), was a would-be mobster of Italian descent who died in prison from pneumonia a year before Darin's birth. His maternal grandmother, Vivian Fern Walden, who called herself "Polly" and was born in 1891, was of English ancestry. She was a vaudeville singer. Darin's birth mother, Vanina Juliette "Nina" Cassotto (born November 30, 1917), became pregnant with him in the summer of 1935, when she was 17. Nina and her mother hatched a plan to pass her baby off as Nina's younger brother.